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Computer cooling

Removal of waste heat from a computer

A finned air cooled heatsinkwith fan clipped onto a CPU, with a smaller passive heatsink without fan in the background
A 3-fan heatsink mounted on a video cardto maximize cooling efficiency of the GPU and surrounding components

Computer cooling is required to remove the waste heat produced by computer components, to keep components within permissible operating temperature limits. Components that are susceptible to temporary malfunction or permanent failure if overheated include integrated circuits such as central processing units (CPUs), chipsets, graphics cards, and hard disk drives.

Components are often designed to generate as little heat as possible, and computers and operating systems may be designed to reduce power consumption and consequent heating according to workload, but more heat may still be produced than can be removed without attention to cooling. Use of heatsinks cooled by airflow reduces the temperature rise produced by a given amount of heat. Attention to patterns of airflow can prevent the development of hotspots. Computer fans are widely used along with heatsink fans to reduce temperature by actively exhausting hot air. There are also more exotic cooling techniques, such as liquid cooling. All modern day processors are designed to cut out or reduce their voltage or clock speed if the internal temperature of the processor exceeds a specified limit. This is generally known as Thermal Throttling, in the case of reduction of clock speeds or Thermal Shutdown in the case of a complete shutdown of the device or system.

Cooling may be designed to reduce the ambient temperature within the case of a computer, such as by exhausting hot air, or to cool a single component or small area (spot cooling). Components commonly individually cooled include the CPU, graphics processing unit (GPU) and the northbridge.

Generators of unwanted heat[edit]

Integrated circuits (e.g. CPU and GPU) are the main generators of heat in modern computers. Heat generation can be reduced by efficient design and selection of operating parameters such as voltage and frequency, but ultimately, acceptable performance can often only be achieved by managing significant heat generation.

The dustbuildup on this laptop CPU heatsink after three years of use has made the laptop unusable due to frequent thermal shutdowns.

In operation, the temperature of a computer's components will rise until the heat transferred to the surroundings is equal to the heat produced by the component, that is, when thermal equilibrium is reached. For reliable operation, the temperature must never exceed a specified maximum permissible value unique to each component. For semiconductors, instantaneous junction temperature, rather than component case, heatsink, or ambient temperature is critical.

Cooling can be impaired by:

  • Dust acting as a thermal insulator and impeding airflow, thereby reducing heatsink and fan performance.
  • Poor airflow including turbulence due to friction against impeding components such as ribbon cables, or incorrect orientation of fans, can reduce the amount of air flowing through a case and even create localized whirlpools of hot air in the case. In some cases of equipment with bad thermal design, cooling air can easily flow out through "cooling" holes before passing over hot components; cooling in such cases can often be improved by blocking of selected holes.
  • Poor heat transfer due to poor thermal contact between components to be cooled and cooling devices. This can be improved by the use of thermal compounds to even out surface imperfections, or even by lapping.

Damage prevention[edit]

Because high temperatures can significantly reduce life span or cause permanent damage to components, and the heat output of components can sometimes exceed the computer's cooling capacity, manufacturers often take additional precautions to ensure that temperatures remain within safe limits. A computer with thermal sensors integrated in the CPU, motherboard, chipset, or GPU can shut itself down when high temperatures are detected to prevent permanent damage, although this may not completely guarantee long-term safe operation. Before an overheating component reaches this point, it may be "throttled" until temperatures fall below a safe point using dynamic frequency scaling technology. Throttling reduces the operating frequency and voltage of an integrated circuit or disables non-essential features of the chip to reduce heat output, often at the cost of slightly or significantly reduced performance. For desktop and notebook computers, throttling is often controlled at the BIOS level. Throttling is also commonly used to manage temperatures in smartphones and tablets, where components are packed tightly together with little to no active cooling, and with additional heat transferred from the hand of the user.[1]

Mainframes and supercomputers[edit]

As electronic computers became larger and more complex, cooling of the active components became a critical factor for reliable operation. Early vacuum-tube computers, with relatively large cabinets, could rely on natural or forced air circulation for cooling. However, solid-state devices were packed much more densely and had lower allowable operating temperatures.

Starting in 1965, IBM and other manufacturers of mainframe computers sponsored intensive research into the physics of cooling densely packed integrated circuits. Many air and liquid cooling systems were devised and investigated, using methods such as natural and forced convection, direct air impingement, direct liquid immersion and forced convection, pool boiling, falling films, flow boiling, and liquid jet impingement. Mathematical analysis was used to predict temperature rises of components for each possible cooling system geometry.[2]

IBM developed three generations of the Thermal Conduction Module (TCM) which used a water-cooled cold plate in direct thermal contact with integrated circuit packages. Each package had a thermally conductive pin pressed onto it, and helium gas surrounded chips and heat-conducting pins. The design could remove up to 27 watts from a chip and up to 2000 watts per module, while maintaining chip package temperatures of around 50 °C (122 °F). Systems using TCMs were the 3081 family (1980), ES/3090 (1984) and some models of the ES/9000 (1990).[2] In the IBM 3081 processor, TCMs allowed up to 2700 watts on a single printed circuit board while maintaining chip temperature at 69 °C (156 °F).[3] Thermal conduction modules using water cooling were also used in mainframe systems manufactured by other companies including Mitsubishi and Fujitsu.

The Cray-1supercomputer designed in 1976 had a distinctive cooling system. The machine was only 77 inches (2,000 mm) in height and 56+1⁄2 inches (1,440 mm) in diameter, and consumed up to 115 kilowatts; this is comparable to the average power consumption of a few dozen Western homes or a medium-sized car. The integrated circuits used in the machine were the fastest available at the time, using emitter-coupled logic; however, the speed was accompanied by high power consumption compared to later CMOS devices.

Heat removal was critical. Refrigerant was circulated through piping embedded in vertical cooling bars in twelve columnar sections of the machine. Each of the 1662 printed circuit modules of the machine had a copper core and was clamped to the cooling bar. The system was designed to maintain the cases of integrated circuits at no more than 54 °C (129 °F), with refrigerant circulating at 21 °C (70 °F). Final heat rejection was through a water-cooled condenser.[4] Piping, heat exchangers, and pumps for the cooling system were arranged in an upholstered bench seat around the outside of the base of the computer. About 20 percent of the machine's weight in operation was refrigerant.[5]

In the later Cray-2, with its more densely packed modules, Seymour Cray had trouble effectively cooling the machine using the metal conduction technique with mechanical refrigeration, so he switched to 'liquid immersion' cooling. This method involved filling the chassis of the Cray-2 with a liquid called Fluorinert. Fluorinert, as its name implies, is an inert liquid that does not interfere with the operation of electronic components. As the components came to operating temperature, the heat would dissipate into the Fluorinert, which was pumped out of the machine to a chilled water heat exchanger.[6]

Performance per watt of modern systems has greatly improved; many more computations can be carried out with a given power consumption than was possible with the integrated circuits of the 1980s and 1990s. Recent supercomputer projects such as Blue Gene rely on air cooling, which reduces cost, complexity, and size of systems compared to liquid cooling.

Air cooling[edit]

Further information: Computer fan


Fans are used when natural convection is insufficient to remove heat. Fans may be fitted to the computer case or attached to CPUs, GPUs, chipsets, power supply units (PSUs), hard drives, or as cards plugged into an expansion slot. Common fan sizes include 40, 60, 80, 92, 120, and 140 mm. 200, 230, 250 and 300 mm fans are sometimes used in high-performance personal computers.

Performance of fans in chassis[edit]

Typical fan curves and chassis impedance curves

A computer has a certain resistance to air flowing through the chassis and components. This is the sum of all the smaller impediments to air flow, such as the inlet and outlet openings, air filters, internal chassis, and electronic components. Fans are simple air pumps that provide pressure to the air of the inlet side relative to the output side. That pressure difference moves air through the chassis, with air flowing to areas of lower pressure.

Fans generally have two published specifications: free air flow and maximum differential pressure. Free air flow is the amount of air a fan will move with zero back-pressure. Maximum differential pressure is the amount of pressure a fan can generate when completely blocked. In between these two extremes are a series of corresponding measurements of flow versus pressure which is usually presented as a graph. Each fan model will have a unique curve, like the dashed curves in the adjacent illustration.[7]

Parallel vis-à-vis series installation[edit]

Fans can be installed parallel to each other, in series, or a combination of both. Parallel installation would be fans mounted side by side. Series installation would be a second fan in line with another fan such as an inlet fan and an exhaust fan. To simplify the discussion, it is assumed the fans are the same model.

Parallel fans will provide double the free air flow but no additional driving pressure. Series installation, on the other hand, will double the available static pressure but not increase the free air flow rate. The adjacent illustration shows a single fan versus two fans in parallel with a maximum pressure of 0.15 inches (3.8 mm) of water and a doubled flow rate of about 72 cubic feet per minute (2.0 m3/min).

Note that air flow changes as the square root of the pressure. Thus, doubling the pressure will only increase the flow 1.41 (√2) times, not twice as might be assumed. Another way of looking at this is that the pressure must go up by a factor of four to double the flow rate.

To determine flow rate through a chassis, the chassis impedance curve can be measured by imposing an arbitrary pressure at the inlet to the chassis and measuring the flow through the chassis. This requires fairly sophisticated equipment. With the chassis impedance curve (represented by the solid red and black lines on the adjacent curve) determined, the actual flow through the chassis as generated by a particular fan configuration is graphically shown where the chassis impedance curve crosses the fan curve. The slope of the chassis impedance curve is a square root function, where doubling the flow rate required four times the differential pressure.

In this particular example, adding a second fan provided marginal improvement with the flow for both configurations being approximately 27–28 cubic feet per minute (0.76–0.79 m3/min). While not shown on the plot, a second fan in series would provide slightly better performance than the parallel installation.[citation needed]

Temperature vis-à-vis flow rate[edit]

The equation for required airflow through a chassis is

CFM={\frac {Q}{Cp\times r\times DT}}


CFM = Cubic Feet per Minute (0.028 m3/min) Q = Heat Transferred (kW) Cp = Specific Heat of Air r = Density DT = Change in Temperature (in °F)

A simple conservative rule of thumb for cooling flow requirements, discounting such effects as heat loss through the chassis walls and laminar versus turbulent flow, and accounting for the constants for specific heat and density at sea level is:

CFM={\frac {3.16\times W}{{\text{allowed temperature rise in}}^{\circ }F}}

CFM={\frac {1.76\times W}{{\text{allowed temperature rise in}}^{\circ }C}}

For example, a typical chassis with 500 watts of load, 130 °F (54 °C) maximum internal temperature in a 100 °F (38 °C) environment, i.e. a difference of 30 °F (17 °C):

CFM={\frac {3.16\times 500W}{(130-100)}}=53

This would be actual flow through the chassis and not the free air rating of the fan. It should also be noted that "Q", the heat transferred, is a function of the heat transfer efficiency of a CPU or GPU cooler to the airflow.

Piezoelectric pump[edit]

A "dual piezo cooling jet", patented by GE, uses vibrations to pump air through the device. The initial device is three millimetres thick and consists of two nickel discs that are connected on either side to a sliver of piezoelectric ceramics. An alternating current passed through the ceramic component causes it to expand and contract at up to 150 times per second so that the nickel discs act like a bellows. Contracted, the edges of the discs are pushed together and suck in hot air. Expanding brings the nickel discs together, expelling the air at high velocity.

The device has no bearings and does not require a motor. It is thinner and consumes less energy than typical fans. The jet can move the same amount of air as a cooling fan twice its size while consuming half as much electricity and at lower cost.[8]

Passive cooling[edit]

Mainboardof a NeXTcubecomputer (1990) with 32 bit microprozessor Motorola 68040operated at 25 MHz. At the lower edge of the image and left from the middle, the heat sink mounted directly on the CPU can be seen. There was no dedicated fan for the CPU. The only other IC with a heat sink is the RAMDAC(right from CPU).

See also: Passive cooling

Passive heatsink cooling involves attaching a block of machined or extruded metal to the part that needs cooling. A thermal adhesive may be used. More commonly for a personal computer CPU, a clamp holds the heatsink directly over the chip, with a thermal grease or thermal pad spread between. This block has fins and ridges to increase its surface area. The heat conductivity of metal is much better than that of air, and it radiates heat better than the component that it is protecting (usually an integrated circuit or CPU). Fan-cooled aluminium heatsinks were originally the norm for desktop computers, but nowadays many heatsinks feature copper base-plates or are entirely made of copper.

Dust buildup between the metal fins of a heatsink gradually reduces efficiency, but can be countered with a gas duster by blowing away the dust along with any other unwanted excess material.

Passive heatsinks are commonly found on older CPUs, parts that do not get very hot (such as the chipset), and low-power computers.

Usually a heatsink is attached to the integrated heat spreader (IHS), essentially a large, flat plate attached to the CPU, with conduction paste layered between. This dissipates or spreads the heat locally. Unlike a heatsink, a spreader is meant to redistribute heat, not to remove it. In addition, the IHS protects the fragile CPU.

Passive cooling involves no fan noise as convection forces move air over the heatsink.

Other techniques[edit]

Liquid immersion cooling[edit]

Main article: Server immersion cooling

A computer immersed in Mineral Oil.

Another growing trend due to the increasing heat density of computers, GPUs, FPGAs, and ASICs is to immerse the entire computer or select components in a thermally, but not electrically, conductive liquid. Although rarely used for the cooling of personal computers,[9] liquid immersion is a routine method of cooling large power distribution components such as transformers. It is also becoming popular with data centers.[10][11] Personal computers cooled in this manner may not require either fans or pumps, and may be cooled exclusively by passive heat exchange between the computer hardware and the enclosure it is placed in.[11][12] A heat exchanger (i.e. heater core or radiator) might still be needed though, and the piping also needs to be placed correctly.[13]

The coolant used must have sufficiently low electrical conductivity not to interfere with the normal operation of the computer. If the liquid is somewhat electrically conductive, it may cause electrical shorts between components or traces and permanently damage them.[14] For these reasons, it is preferred that the liquid be an insulator (dielectric) and not conduct electricity.

A wide variety of liquids exist for this purpose, including transformer oils, synthetic single-phase and dual phase dielectric coolants such as 3MFluorinert or 3M Novec. Non-purpose oils, including cooking, motor and silicone oils, have been successfully used for cooling personal computers.

Some fluids used in immersion cooling, especially hydrocarbon based materials such as mineral oils, cooking oils, and organic esters, may degrade some common materials used in computers such as rubbers, polyvinyl chloride (PVC), and thermal greases. Therefore it is critical to review the material compatibility of such fluids prior to use. Mineral oil in particular has been found to have negative effects on PVC and rubber-based wire insulation.[15] Thermal pastes used to transfer heat to heatsinks from processors and graphic cards has been reported to dissolve in some liquids, however with negligible impact to cooling, unless the components were removed and operated in air.[16]

Evaporation, especially for 2-phase coolants, can pose a problem,[17] and the liquid may require either to be regularly refilled or sealed inside the computer's enclosure. Immersion cooling can allow for extremely low PUE values of 1.05, vs air cooling's 1.35, and allow for up to 100 KW of computing power (heat dissipation, TDP) per 19-inch rack, as opposed to air cooling, which usually handles up to 23 KW.[18]

Waste heat reduction[edit]

Where powerful computers with many features are not required, less powerful computers or ones with fewer features can be used. As of 2011[update] a VIAEPIA motherboard with CPU typically dissipates approximately 25 watts of heat, whereas a more capable Pentium 4 motherboard and CPU typically dissipates around 140 watts. Computers can be powered with direct current from an external power supply unit which does not generate heat inside the computer case. The replacement of cathode ray tube (CRT) displays by more efficient thin-screen liquid crystal display (LCD) ones in the early twenty-first century has reduced power consumption significantly.


Main article: Heat sink

Passive heatsink on a chipset
Active heatsink with a fan and heat pipes

A component may be fitted in good thermal contact with a heatsink, a passive device with large thermal capacity and with a large surface area relative to its volume. Heatsinks are usually made of a metal with high thermal conductivity such as aluminium or copper,[19] and incorporate fins to increase surface area. Heat from a relatively small component is transferred to the larger heatsink; the equilibrium temperature of the component plus heatsink is much lower than the component's alone would be. Heat is carried away from the heatsink by convective or fan-forced airflow. Fan cooling is often used to cool processors and graphics cards that consume significant amounts of electrical energy. In a computer, a typical heat-generating component may be manufactured with a flat surface. A block of metal with a corresponding flat surface and finned construction, sometimes with an attached fan, is clamped to the component. To fill poorly conducting air gaps due to imperfectly flat and smooth surfaces, a thin layer of thermal grease, a thermal pad, or thermal adhesive may be placed between the component and heatsink.

Heat is removed from the heatsink by convection, to some extent by radiation, and possibly by conduction if the heatsink is in thermal contact with, say, the metal case. Inexpensive fan-cooled aluminium heatsinks are often used on standard desktop computers. Heatsinks with copper base-plates, or made of copper, have better thermal characteristics than those made of aluminium. A copper heatsink is more effective than an aluminium unit of the same size, which is relevant with regard to the high-power-consumption components used in high-performance computers.

Passive heatsinks are commonly found on: older CPUs, parts that do not dissipate much power, such as the chipset, computers with low-power processors, and equipment where silent operation is critical and fan noise unacceptable.

Usually a heatsink is clamped to the integrated heat spreader (IHS), a flat metal plate the size of the CPU package which is part of the CPU assembly and spreads the heat locally. A thin layer of thermal compound is placed between them to compensate for surface imperfections. The spreader's primary purpose is to redistribute heat. The heatsink fins improve its efficiency.

Several brands of DDR2, DDR3, DDR4 and the upcoming DDR5 DRAM memory modules are fitted with a finned heatsink clipped onto the top edge of the module. The same technique is used for video cards that use a finned passive heatsink on the GPU.

Dust tends to build up in the crevices of finned heatsinks, particularly with the high airflow produced by fans. This keeps the air away from the hot component, reducing cooling effectiveness; however, removing the dust restores effectiveness.

Peltier (thermoelectric) cooling[edit]

Main article: Thermoelectric cooling

Regular Peltier cooling setup for PCs

Peltier junctions are generally only around 10-15% as efficient as the ideal refrigerator (Carnot cycle), compared with 40–60% achieved by conventional compression cycle systems (reverse Rankine systems using compression/expansion).[20] Due to this lower efficiency, thermoelectric cooling is generally only used in environments where the solid state nature (no moving parts, low maintenance, compact size, and orientation insensitivity) outweighs pure efficiency.

Modern TECs use several stacked units each composed of dozens or hundreds of thermocouples laid out next to each other, which allows for a substantial amount of heat transfer. A combination of bismuth and tellurium is most commonly used for the thermocouples.

As active heat pumps which consume power, TECs can produce temperatures below ambient, impossible with passive heatsinks, radiator-cooled liquid cooling, and heatpipe HSFs. However, while pumping heat, a Peltier module will typically consume more electric power than the heat amount being pumped.

It is also possible to use a Peltier element together with a high pressure refrigerant (two phase cooling) to cool the CPU.[21][22]

Liquid cooling[edit]

Further information on water cooling: Water cooling

Deepcool Captain 360, an all-in-one cooling unit, installed in a case
DIY water cooling setup showing a 12 V pump, CPU waterblockand the typical application of a T-Line
Schematic of a regular liquid cooling setup for PCs

Liquid cooling is a highly effective method of removing excess heat, with the most common heat transfer fluid in desktop PCs being (distilled) water. The advantages of water cooling over air cooling include water's higher specific heat capacity and thermal conductivity.

The principle used in a typical (active) liquid cooling system for computers is identical to that used in an automobile's internal combustion engine, with the water being circulated by a water pump through a waterblock mounted on the CPU (and sometimes additional components as GPU and northbridge)[23] and out to a heat exchanger, typically a radiator. The radiator is itself usually cooled additionally by means of a fan.[23] Besides a fan, it could possibly also be cooled by other means, such as a Peltier cooler (although Peltier elements are most commonly placed directly on top of the hardware to be cooled, and the coolant is used to conduct the heat away from the hot side of the Peltier element).[24][25] A coolant reservoir is often also connected to the system.[26]

Besides active liquid cooling systems, passive liquid cooling systems are also sometimes used.[27][28][29][30][31] These systems often discard a fan or a water pump, hence theoretically increasing the reliability of the system, and/or making it quieter than active systems. Downsides of these systems however are that they are much less efficient in discarding the heat and thus also need to have much more coolant - and thus a much bigger coolant reservoir - giving the coolant more time to cool down.

Liquids allow the transfer of more heat from the parts being cooled than air, making liquid cooling suitable for overclocking and high performance computer applications.[32] Compared to air cooling, liquid cooling is also influenced less by the ambient temperature.[33] Liquid cooling's comparatively low noise-level compares favourably to that of air cooling, which can become quite noisy.

Disadvantages of liquid cooling include complexity and the potential for a coolant leak. Leaked water (or more importantly any additives in the water) can damage any electronic components with which it comes into contact, and the need to test for and repair leaks makes for more complex and less reliable installations. (Notably, the first major foray into the field of liquid-cooled personal computers for general use, the high-end versions of Apple's Power Mac G5, was ultimately doomed by a propensity for coolant leaks.[34]) An air-cooled heatsink is generally much simpler to build, install, and maintain than a water cooling solution,[35] although CPU-specific water cooling kits can also be found, which may be just as easy to install as an air cooler. These are not limited to CPUs, however, and liquid cooling of GPU cards is also possible.[36]

While originally limited to mainframe computers, liquid cooling has become a practice largely associated with overclocking in the form of either manufactured kits, or in the form of do-it-yourself setups assembled from individually gathered parts. The past few years have seen an increase in the popularity of liquid cooling in pre-assembled, moderate to high performance, desktop computers. Sealed ("closed-loop") systems incorporating a small pre-filled radiator, fan, and waterblock simplify the installation and maintenance of water cooling at a slight cost in cooling effectiveness relative to larger and more complex setups. Liquid cooling is typically combined with air cooling, using liquid cooling for the hottest components, such as CPUs or GPUs, while retaining the simpler and cheaper air cooling for less demanding components.

The IBM Aquasar system uses hot water cooling to achieve energy efficiency, the water being used to heat buildings as well.[37][38]

Since 2011, the effectiveness of water cooling has prompted a series of all-in-one (AIO) water cooling solutions.[39] AIO solutions result in a much simpler to install unit, and most units have been reviewed positively by review sites.

Heat pipes and vapor chambers[edit]

Main article: Heat pipe

A graphics card with a fanless heatpipe cooler design

A heat pipe is a hollow tube containing a heat transfer liquid. The liquid absorbs heat and evaporates at one end of the pipe. The vapor travels to the other (cooler) end of the tube, where it condenses, giving up its latent heat. The liquid returns to the hot end of the tube by gravity or capillary action and repeats the cycle. Heat pipes have a much higher effective thermal conductivity than solid materials. For use in computers, the heatsink on the CPU is attached to a larger radiator heatsink. Both heatsinks are hollow, as is the attachment between them, creating one large heat pipe that transfers heat from the CPU to the radiator, which is then cooled using some conventional method. This method is expensive and usually used when space is tight, as in small form-factor PCs and laptops, or where no fan noise can be tolerated, as in audio production. Because of the efficiency of this method of cooling, many desktop CPUs and GPUs, as well as high end chipsets, use heat pipes and vapor chambers in addition to active fan-based cooling and passive heatsinks to remain within safe operating temperatures. A vapor chamber operates on the same principles as a heat pipe but takes on the form of a slab or sheet instead of a pipe. Heat pipes may be placed vertically on top and form part of vapor chambers. Vapor chambers may also be used on high-end smartphones.

Electrostatic air movement and corona discharge effect cooling[edit]

The cooling technology under development by Kronos and Thorn Micro Technologies employs a device called an ionic wind pump (also known as an electrostatic fluid accelerator). The basic operating principle of an ionic wind pump is corona discharge, an electrical discharge near a charged conductor caused by the ionization of the surrounding air.

The corona discharge cooler developed by Kronos works in the following manner: A high electric field is created at the tip of the cathode, which is placed on one side of the CPU. The high energy potential causes the oxygen and nitrogen molecules in the air to become ionized (positively charged) and create a corona (a halo of charged particles). Placing a grounded anode at the opposite end of the CPU causes the charged ions in the corona to accelerate towards the anode, colliding with neutral air molecules on the way. During these collisions, momentum is transferred from the ionized gas to the neutral air molecules, resulting in movement of gas towards the anode.

The advantages of the corona-based cooler are its lack of moving parts, thereby eliminating certain reliability issues and operating with a near-zero noise level and moderate energy consumption.[40]

Soft cooling[edit]

Soft cooling is the practice of utilizing software to take advantage of CPU power saving technologies to minimize energy use. This is done using halt instructions to turn off or put in standby state CPU subparts that aren't being used or by underclocking the CPU. While resulting in lower total speeds, this can be very useful if overclocking a CPU to improve user experience rather than increase raw processing power, since it can prevent the need for noisier cooling. Contrary to what the term suggests, it is not a form of cooling but of reducing heat creation.


Undervolting is a practice of running the CPU or any other component with voltages below the device specifications. An undervolted component draws less power and thus produces less heat. The ability to do this varies by manufacturer, product line, and even different production runs of the same product (as well as that of other components in the system), but processors are often specified to use voltages higher than strictly necessary. This tolerance ensures that the processor will have a higher chance of performing correctly under sub-optimal conditions, such as a lower-quality motherboard or low power supply voltages. Below a certain limit, the processor will not function correctly, although undervolting too far does not typically lead to permanent hardware damage (unlike overvolting).

Undervolting is used for quiet systems, as less cooling is needed because of the reduction of heat production, allowing noisy fans to be omitted. It is also used when battery charge life must be maximized.


Conventional cooling techniques all attach their "cooling" component to the outside of the computer chip package. This "attaching" technique will always exhibit some thermal resistance, reducing its effectiveness. The heat can be more efficiently and quickly removed by directly cooling the local hot spots of the chip, within the package. At these locations, power dissipation of over 300 W/cm2 (typical CPU is less than 100 W/cm2) can occur, although future systems are expected to exceed 1000 W/cm2.[41] This form of local cooling is essential to developing high power density chips. This ideology has led to the investigation of integrating cooling elements into the computer chip. Currently there are two techniques: micro-channel heatsinks, and jet impingement cooling.

In micro-channel heatsinks, channels are fabricated into the silicon chip (CPU), and coolant is pumped through them. The channels are designed with very large surface area which results in large heat transfers. Heat dissipation of 3000 W/cm2 has been reported with this technique.[42] The heat dissipation can be further increased if two-phase flow cooling is applied. Unfortunately, the system requires large pressure drops, due to the small channels, and the heat flux is lower with dielectric coolants used in electronic cooling.

Another local chip cooling technique is jet impingement cooling. In this technique, a coolant is flowed through a small orifice to form a jet. The jet is directed toward the surface of the CPU chip, and can effectively remove large heat fluxes. Heat dissipation of over 1000 W/cm2 has been reported.[43] The system can be operated at lower pressure in comparison to the micro-channel method. The heat transfer can be further increased using two-phase flow cooling and by integrating return flow channels (hybrid between micro-channel heatsinks and jet impingement cooling).

Phase-change cooling[edit]

Phase-change cooling is an extremely effective way to cool the processor. A vapor compression phase-change cooler is a unit that usually sits underneath the PC, with a tube leading to the processor. Inside the unit is a compressor of the same type as in an air conditioner. The compressor compresses a gas (or mixture of gases) which comes from the evaporator (CPU cooler discussed below). Then, the very hot high-pressure vapor is pushed into the condenser (heat dissipation device) where it condenses from a hot gas into a liquid, typically subcooled at the exit of the condenser then the liquid is fed to an expansion device (restriction in the system) to cause a drop in pressure a vaporize the fluid (cause it to reach a pressure where it can boil at the desired temperature); the expansion device used can be a simple capillary tube to a more elaborate thermal expansion valve. The liquid evaporates (changing phase), absorbing the heat from the processor as it draws extra energy from its environment to accommodate this change (see latent heat). The evaporation can produce temperatures reaching around −15 to −150 °C (5 to −238 °F). The liquid flows into the evaporator cooling the CPU, turning into a vapor at low pressure. At the end of the evaporator this gas flows down to the compressor and the cycle begins over again. This way, the processor can be cooled to temperatures ranging from −15 to −150 °C (5 to −238 °F), depending on the load, wattage of the processor, the refrigeration system (see refrigeration) and the gas mixture used. This type of system suffers from a number of issues (cost, weight, size, vibration, maintenance, cost of electricity, noise, need for a specialized computer tower) but, mainly, one must be concerned with dew point and the proper insulation of all sub-ambient surfaces that must be done (the pipes will sweat, dripping water on sensitive electronics).

Alternately, a new breed of the cooling system is being developed, inserting a pump into the thermosiphon loop. This adds another degree of flexibility for the design engineer, as the heat can now be effectively transported away from the heat source and either reclaimed or dissipated to ambient. Junction temperature can be tuned by adjusting the system pressure; higher pressure equals higher fluid saturation temperatures. This allows for smaller condensers, smaller fans, and/or the effective dissipation of heat in a high ambient temperature environment. These systems are, in essence, the next generation fluid cooling paradigm, as they are approximately 10 times more efficient than single-phase water. Since the system uses a dielectric as the heat transport medium, leaks do not cause a catastrophic failure of the electric system.

This type of cooling is seen as a more extreme way to cool components since the units are relatively expensive compared to the average desktop. They also generate a significant amount of noise, since they are essentially refrigerators; however, the compressor choice and air cooling system is the main determinant of this, allowing for flexibility for noise reduction based on the parts chosen.

A "thermosiphon" traditionally refers to a closed system consisting of several pipes and/or chambers, with a larger chamber containing a small reservoir of liquid (often having a boiling point just above ambient temperature, but not necessarily). The larger chamber is as close to the heat source and designed to conduct as much heat from it into the liquid as possible, for example, a CPU cold plate with the chamber inside it filled with the liquid. One or more pipes extend upward into some sort of radiator or similar heat dissipation area, and this is all set up such that the CPU heats the reservoir and liquid it contains, which begins boiling, and the vapor travels up the tube(s) into the radiator/heat dissipation area, and then after condensing, drips back down into the reservoir, or runs down the sides of the tube. This requires no moving parts, and is somewhat similar to a heat pump, except that capillary action is not used, making it potentially better in some sense (perhaps most importantly, better in that it is much easier to build, and much more customizable for specific use cases and the flow of coolant/vapor can be arranged in a much wider variety of positions and distances, and have far greater thermal mass and maximum capacity compared to heat pipes which are limited by the amount of coolant present and the speed and flow rate of coolant that capillary action can achieve with the wicking used, often sintered copper powder on the walls of the tube, which have a limited flow rate and capacity.)

Liquid nitrogen[edit]

Liquid nitrogen may be used to cool overclocked components

As liquid nitrogen boils at −196 °C (−320.8 °F), far below the freezing point of water, it is valuable as an extreme coolant for short overclocking sessions.

In a typical installation of liquid nitrogen cooling, a copper or aluminium pipe is mounted on top of the processor or graphics card. After the system has been heavily insulated against condensation, the liquid nitrogen is poured into the pipe, resulting in temperatures well below −100 °C (−148 °F).

Evaporation devices ranging from cut out heatsinks with pipes attached to custom milled copper containers are used to hold the nitrogen as well as to prevent large temperature changes. However, after the nitrogen evaporates, it has to be refilled. In the realm of personal computers, this method of cooling is seldom used in contexts other than overclocking trial-runs and record-setting attempts, as the CPU will usually expire within a relatively short period of time due to temperature stress caused by changes in internal temperature.

Although liquid nitrogen is non-flammable, it can condense oxygen directly from air. Mixtures of liquid oxygen and flammable materials can be dangerously explosive.

Liquid nitrogen cooling is, generally, only used for processor benchmarking, due to the fact that continuous usage may cause permanent damage to one or more parts of the computer and, if handled in a careless way, can even harm the user, causing frostbite.

Liquid helium[edit]

Liquid helium, colder than liquid nitrogen, has also been used for cooling. Liquid helium boils at −269 °C (−452.20 °F), and temperatures ranging from −230 to −240 °C (−382.0 to −400.0 °F) have been measured from the heatsink.[44] However, liquid helium is more expensive and more difficult to store and use than liquid nitrogen. Also, extremely low temperatures can cause integrated circuits to stop functioning. Silicon-based semiconductors, for example, will freeze out at around −233 °C (−387.4 °F).[45]


Cooling can be improved by several techniques which may involve additional expense or effort. These techniques are often used, in particular, by those who run parts of their computer (such as the CPU and GPU) at higher voltages and frequencies than specified by manufacturer (overclocking), which increases heat generation.

The installation of higher performance, non-stock cooling may also be considered modding. Many overclockers simply buy more efficient, and often, more expensive fan and heatsink combinations, while others resort to more exotic ways of computer cooling, such as liquid cooling, Peltier effect heatpumps, heat pipe or phase change cooling.

There are also some related practices that have a positive impact in reducing system temperatures:

Thermally conductive compounds[edit]

Main article: thermal compound

Often called Thermal Interface Material (TIM) (e.g. Intel[46]).

Thermal compound is commonly used to enhance the thermal conductivity from the CPU, GPU, or any heat-producing components to the heatsink cooler. (Counterclockwise from top left: ArcticMX-2, ArcticMX-4, Tuniq TX-4, AntecFormula 7, Noctua NT-H1)

Perfectly flat surfaces in contact give optimal cooling, but perfect flatness and absence of microscopic air gaps is not practically possible, particularly in mass-produced equipment. A very thin skim of thermal compound, which is much more thermally conductive than air, though much less so than metal, can improve thermal contact and cooling by filling in the air gaps. If only a small amount of compound just sufficient to fill the gaps is used, the best temperature reduction will be obtained.

There is much debate about the merits of compounds, and overclockers often consider some compounds to be superior to others. The main consideration is to use the minimal amount of thermal compound required to even out surfaces, as the thermal conductivity of compound is typically 1/3 to 1/400 that of metal, though much better than air. The conductivity of the heatsink compound ranges from about 0.5 to 80W/mK[47] (see articles); that of aluminium is about 200, that of air about 0.02. Heat-conductive pads are also used, often fitted by manufacturers to heatsinks. They are less effective than properly applied thermal compound, but simpler to apply and, if fixed to the heatsink, cannot be omitted by users unaware of the importance of good thermal contact, or replaced by a thick and ineffective layer of compound.

Unlike some techniques discussed here, the use of thermal compound or padding is almost universal when dissipating significant amounts of heat.

Heat sink lapping[edit]

Mass-produced CPU heat spreaders and heatsink bases are never perfectly flat or smooth; if these surfaces are placed in the best contact possible, there will be air gaps which reduce heat conduction. This can easily be mitigated by the use of thermal compound, but for the best possible results surfaces must be as flat as possible. This can be achieved by a laborious process known as lapping, which can reduce CPU temperature by typically 2 °C (4 °F).[48]

Rounded cables[edit]

Most older PCs use flat ribbon cables to connect storage drives (IDE or SCSI). These large flat cables greatly impede airflow by causing drag and turbulence. Overclockers and modders often replace these with rounded cables, with the conductive wires bunched together tightly to reduce surface area. Theoretically, the parallel strands of conductors in a ribbon cable serve to reduce crosstalk (signal carrying conductors inducing signals in nearby conductors), but there is no empirical evidence of rounding cables reducing performance. This may be because the length of the cable is short enough so that the effect of crosstalk is negligible. Problems usually arise when the cable is not electromagnetically protected and the length is considerable, a more frequent occurrence with older network cables.

These computer cables can then be cable tied to the chassis or other cables to further increase airflow.

This is less of a problem with new computers that use serial ATA which has a much narrower cable.


The colder the cooling medium (the air), the more effective the cooling. Cooling air temperature can be improved with these guidelines:

  • Supply cool air to the hot components as directly as possible. Examples are air snorkels and tunnels that feed outside air directly and exclusively to the CPU or GPU cooler. For example, the BTX case design prescribes a CPU air tunnel.
  • Expel warm air as directly as possible. Examples are: Conventional PC (ATX) power supplies blow the warm air out the back of the case. Many dual-slot graphics card designs blow the warm air through the cover of the adjacent slot. There are also some aftermarket coolers that do this. Some CPU cooling designs blow the warm air directly towards the back of the case, where it can be ejected by a case fan.
  • Air that has already been used to spot-cool a component should not be reused to spot-cool a different component (this follows from the previous items). The BTX case design violates this rule, since it uses the CPU cooler's exhaust to cool the chipset and often the graphics card. One may come across old or ultra-low-budget ATX cases which feature a PSU mount in the top. Most modern ATX cases do however have a PSU mount in the bottom of the case with a filtered air vent directly beneath the PSU.
  • Prefer cool intake air, avoid inhaling exhaust air (outside air above or near the exhausts). For example, a CPU cooling air duct at the back of a tower case would inhale warm air from a graphics card exhaust. Moving all exhausts to one side of the case, conventionally the back/top, helps to keep the intake air cool.
  • Hiding cables behind motherboard tray or simply apply ziptie and tucking cables away to provide unhindered airflow.

Fewer fans but strategically placed will improve the airflow internally within the PC and thus lower the overall internal case temperature in relation to ambient conditions. The use of larger fans also improves efficiency and lowers the amount of waste heat along with the amount of noise generated by the fans while in operation.

There is little agreement on the effectiveness of different fan placement configurations, and little in the way of systematic testing has been done. For a rectangular PC (ATX) case, a fan in the front with a fan in the rear and one in the top has been found to be a suitable configuration. However, AMD's (somewhat outdated) system cooling guidelines notes that "A front cooling fan does not seem to be essential. In fact, in some extreme situations, testing showed these fans to be recirculating hot air rather than introducing cool air."[49] It may be that fans in the side panels could have a similar detrimental effect—possibly through disrupting the normal air flow through the case. However, this is unconfirmed and probably varies with the configuration.

Air pressure[edit]

1) Negative pressure     2) Positive pressure

Loosely speaking, positive pressure means intake into the case is stronger than exhaust from the case. This configuration results in pressure inside of the case being higher than in its environment. Negative pressure means exhaust is stronger than intake. This results in internal air pressure being lower than in the environment. Both configurations have benefits and drawbacks, with positive pressure being the more popular of the two configurations. Negative pressure results in the case pulling air through holes and vents separate from the fans, as the internal gases will attempt to reach an equilibrium pressure with the environment. Consequently, this results in dust entering the computer in all locations. Positive pressure in combination with filtered intake solves this issue, as air will only incline to be exhausted through these holes and vents in order to reach an equilibrium with its environment. Dust is then unable to enter the case except through the intake fans, which need to possess dust filters.

Computer types[edit]


Illustration of the airflow of the cooling air in a computer case during computer cooling

Desktop computers typically use one or more fans for cooling. While almost all desktop power supplies have at least one built-in fan, power supplies should never draw heated air from within the case, as this results in higher PSU operating temperatures which decrease the PSU's energy efficiency, reliability and overall ability to provide a steady supply of power to the computer's internal components. For this reason, all modern ATX cases (with some exceptions found in ultra-low-budget cases) feature a power supply mount in the bottom, with a dedicated PSU air intake (often with its own filter) beneath the mounting location, allowing the PSU to draw cool air from beneath the case.

Most manufacturers recommend bringing cool, fresh air in at the bottom front of the case, and exhausting warm air from the top rear[citation needed]. If fans are fitted to force air into the case more effectively than it is removed, the pressure inside becomes higher than outside, referred to as a "positive" airflow (the opposite case is called "negative" airflow). Worth noting is that positive internal pressure only prevents dust accumulating in the case if the air intakes are equipped with dust filters.[50] A case with negative internal pressure will suffer a higher rate of dust accumulation even if the intakes are filtered, as the negative pressure will draw dust in through any available opening in the case

The air flow inside the typical desktop case is usually not strong enough for a passive CPU heatsink. Most desktop heatsinks are active including one or even multiple directly attached fans or blowers.


A server with seven fans in the middle of the chassis, between drives on the right and main motherboard on the left

Close view of server coolers

Server coolers[edit]

Each server can have an independent internal cooler system; Server cooling fans in (1 U) enclosures are usually located in the middle of the enclosure, between the hard drives at the front and passive CPU heatsinks at the rear. Larger (higher) enclosures also have exhaust fans, and from approximately 4U they may have active heatsinks. Power supplies generally have their own rear-facing exhaust fans.

Rack-mounted coolers[edit]

Rack cabinet is a typical enclosure for horizontally mounted servers. Air typically drawn in at the front of the rack and exhausted at the rear. Each cabinet can have additional cooling options; for example, they can have a Close Coupled Cooling attachable module or integrated with cabinet elements (like cooling doors in iDataPlex server rack).

Another way of accommodating large numbers of systems in a small space is to use blade chassis, oriented vertically rather than horizontally, to facilitate convection. Air heated by the hot components tends to rise, creating a natural air flow along the boards (stack effect), cooling them. Some manufacturers take advantage of this effect.[51][52]

Data center cooling[edit]

Because data centers typically contain large numbers of computers and other power-dissipating devices, they risk equipment overheating; extensive HVAC systems are used to prevent this. Often a raised floor is used so the area under the floor may be used as a large plenum for cooled air and power cabling.

Direct Contact Liquid Cooling has emerged more efficient than air cooling options, resulting in smaller footprint, lower capital requirements and lower operational costs than air cooling. It uses warm liquid instead of air to move heat away from the hottest components. Energy efficiency gains from liquid cooling is also driving its adoption.[53][54]


A laptop computer's CPU and GPU heatsinks, and copper heat pipes transferring heat to an exhaust fan expelling hot air
The heat is expelled from a laptop by an exhaust centrifugal fan.

Laptops present a difficult mechanical airflow design, power dissipation, and cooling challenge. Constraints specific to laptops include: the device as a whole has to be as light as possible; the form factor has to be built around the standard keyboard layout; users are very close, so noise must be kept to a minimum, and the case exterior temperature must be kept low enough to be used on a lap. Cooling generally uses forced air cooling but heat pipes and the use of the metal chassis or case as a passive heatsink are also common. Solutions to reduce heat include using lower power-consumption ARM or Intel Atom processors.

Mobile devices[edit]

Mobile devices usually have no discrete cooling systems, as mobile CPU and GPU chips are designed for maximum power efficiency due to the constraints of the device's battery. Some higher performance devices may include a heat spreader that aids in transferring heat to the external case of a phone or tablet.

See also[edit]


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  19. ^The thermal conductivity and thermal capacity of silver is better than that of copper, which is better than that of aluminium (see List of thermal conductivities). Consequently on purely technical grounds, solid silver (silver-plating is pointless) is better than copper, which is better than aluminium, for heatsinks and also for saucepans. Cost, of course, rules out silver, although enthusiasts have used silver heatsinks and silver saucepans are used for cooking when cost is not an issueArchived 16 July 2015 at the Wayback Machine
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External links[edit]

Sours: https://en.wikipedia.org/wiki/Computer_cooling

How Liquid-cooled PCs Work

Whether you're using a desktop or laptop computer, there's a good chance that if you stop what you're doing and listen carefully, you'll hear the whirring of a small fan. If your computer has a high-end video card and lots of processing power, you might even hear more than one.

In most computers, fans do a pretty good job of keeping electronic components cool. But for people who want to use high-end hardware or to coax their PCs into running faster, a fan might not have enough power for the job. If a computer generates too much heat, liquid cooling — also known as water cooling — can be a better solution.

It might seem a little counterintuitive to put liquids near delicate electronic equipment but cooling with water is far more efficient than cooling with air.

A liquid-cooling system for a PC works a lot like the cooling system of a car. Both take advantage of a basic principle of thermodynamics — that heat moves from warmer objects to cooler objects. As the cooler object gets warmer, the warmer object gets cooler. You can experience this principle firsthand by putting your hand flat on a cool spot on your desk for several seconds. When you lift your hand, your palm will be a little cooler, and the spot where your hand was will be a little warmer.

Liquid cooling is a very common process. A car's cooling system circulates water, usually mixed with antifreeze, through the engine. Hot surfaces in the engine warm the water, cooling off in the process.

The water circulates from the engine to the radiator, a system of fans and tubes with a lot of exterior surface area. Heat moves from the hot water to the radiator, causing the water to cool off. The cool water then heads back to the engine. At the same time, a fan moves air over the outside of the radiator. The radiator warms the air, cooling itself off at the same time. In this way, the engine's heat moves out of the cooling system and into the surrounding air. Without the radiator's surfaces contacting the air and dispelling the heat, the system would just move the heat around instead of getting rid of it.

A car engine generates heat as a byproduct of burning fuel. Computer components, on the other hand, generate heat as a byproduct of moving electrons around. A computer's microchips are full of electrical transistors, which are basically electrical switches that are either on or off. As transistors change their states between on and off, electricity moves around in the microchip. The more transistors a chip contains and the faster they change states, the hotter the microchip gets. Like a car engine, if the chip gets too hot, it will fail.

Sours: https://computer.howstuffworks.com/liquid-cooled-pc.htm
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Best CPU coolers in 2021

The best CPU coolers do just that, keep your CPU cool. Whether you have an Intel or AMD chip at the heart of your gaming rig, getting a handle on your PC's thermals will save you a headache down the road. If you want the most of your CPU, ditch the stock cooler and invest in one of these third-party chip chillers we tested this year.

There are two types of CPU coolers out there. Air coolers and liquid coolers. Air coolers are the most common. A metal heat sink pulls heat away from the CPU then blows it away with a fan. You need to consider your CPU socket type, RAM, case dimensions, and the current airflow inside your machine with air coolers. 

The other, more luxurious options are liquid coolers, usually in the AIO (all-in-one) variety. Liquid cooling is often a more efficient choice and can lead to some flashy-looking components with wild RGB lighting options and even OLED screens. If you're feeling exceptionally courageous, you could also create a complete custom water cooling loop, which can include GPU as well as CPU cooling. Still, that way lies tube-bending and a whole lot of installation effort—not recommended for first-time PC builders. 

Each of the coolers below was put through rigorous testing on our PC Gamer test rigs so we can tell you which ones offer the most optimum CPU cooling for your dollars under different workloads. If you're looking for other ways to help increase your system's cooling performance, you can check out our guide to the best PC fans.  

Best CPU coolers

1. Corsair H115i RGB Platinum

The best liquid CPU cooler


Type: Liquid cooling

Compatibility: Intel 1366, 115x, 2011, 2066; AMD AM2, AM3, AM4, sTR4

Fan speed: 360-2,200 RPM

Noise volume: 28-50 dBA

Dimensions: 280 x 120 x 30 mm

Weight: 1.8 lbs (830 g)

Reasons to buy

+RGB lighting on fans and CPU block+Available in a stunning white variation+Top notch cooling performance

Reasons to avoid

-RGB lighting isn't for everyone

Corsair was one of the first hardware manufacturers to bring all-in-one liquid coolers to market. It only fits that its latest cooler has dethroned our previous king. The H115i has always been a strong contender for the throne of best liquid CPU cooler, only narrowly beaten by NZXT's Kraken X62.

The updated H115i Platinum is a definite improvement, but NZXT's infinity mirror CPU block design was and remained one of the most beautiful RGB implementations we’ve seen in any product. It wasn't until seeing Corsair’s latest contender, the H115i Platinum, that we’ve been able to let the Kraken go.

For now, though, it's all about the excellent Corsair AIO. The H115i Platinum is available in black or white with a set of addressable RGB LED fans and CPU block. It’s a real head-turner in any build and has excellent software and performance to back it up.    

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2. Noctua NH-D15

The best air cooler in 2021


Type: Fan and heatsink

Compatibility: Intel LGA 1150 – 2066; AMD AM2 – AM4, FM1 – FM2+

Fan speed: 300-1500 RPM

Noise volume: Up to 24.6 dBA

Dimensions: 165 x 150 x 161 mm

Weight: 2.91 lbs (1.32 kg)

Reasons to buy

+ Super-quiet performance+ Dual 140 mm fans included 

It may be one of the most expensive air coolers we've tested, but Noctua's flagship NH-D15 is our top choice for high-end air coolers. Based on the company's award-winning D14, the NH-D15 performs just as well as a handful of all-in-one liquid coolers and even beats a few of them both in performance and noise levels. The cooler features a dual tower heatsink and comes with two high airflow 140mm fans.

Even working at 100 percent, the cooler ran quieter than just about all of its competitors. If you aren't a fan of liquid cooling or don't have the space to mount a radiator, the NH-D15 is about as good as it gets for air cooling. The only downside we could find is its bulkiness, which could cause problems with tall RAM module clearance.

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3. EVGA CLC 240

Liquid cooling at an affordable price


Type: Liquid cooling

Compatibility: Intel LGA2066/2011/2011-v3/1150/1151/1155/1156/1366 AMD AM2-AM4, FM1-FM2, TR4

Fan speed: 500-2400 RPM

Noise volume: 16-40 dBA

Dimensions: 276 x 122 x 53 mm

Weight: 1.8 lbs (820 g)

Reasons to buy

+ Very affordable + RGB pump head 

Reasons to avoid

-Bare bones

EVGA's latest CLC liquid coolers are our favorite mid-range pick because of their excellent performance per dollar. Matching cooling of the latest chip-chillers from Corsair and NZXT, the 240mm CLC costs a fraction of the price while only sacrificing a few features. The included fans can get very loud at full speed, but we found the cooler to run well enough without ever reaching those levels.

While you won't get the fancy addressable RGB lighting you'd find in NZXT, Thermaltake, or Cooler Master's latest designs, the EVGA CLC does have the same sleeved tubing and a single RGB light on the pump head that can be controlled through the software. If you don't care for all of the bells and whistles, EVGA's CLC 240 offers exceptional performance with little compromises.

Best mid-tower case | Best RAM for gaming | Best SSD for gaming  
Best gaming monitor| Best CPU for gaming | Best gaming headset

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4. Noctua NH-P1

The best passive CPU cooler


Type: Passive air cooling

Compatibility: Intel LGA 1200, 115x, 2011/2066; AMD AM2-AM4

Fan speed: NA

Noise volume: Silent

Dimensions: 158 x 154 x 152 mm

Weight: 1800 g

Reasons to buy

+Completely silent+Compatible with high-end CPUs+Plenty cool enough for gaming workloads

Reasons to avoid

-Large-Requires a case with good airflow

The Noctua NH-P1 is certainly a niche CPU cooler, but it's also an exciting one in that it shakes up what a completely silent chip chiller is capable of. Previously, if you wanted a passive cooler you would either have to pair it with an underpowered processor, or you would have to seriously limit the clock speed of your chip.

The Noctua NH-P1, however, is capable of coping with relatively high-end CPUs, and running them at, or very close to, their standard performance. Essentially, this is a passive cooler that can actually keep a decent gaming processor powered up. We've tested the NH-P1 on our Core i7 10700K open test bench—which has no fans, and therefore completely unoptimised airflow—and while it may throttle on seriously CPU intensive benchmarks, it absolutely flew on our standard gaming tests.

That chip is slightly over Noctua's own recommendations for the NH-P1, but you can check out its compatibility centre to see whether your CPU will be supported by this chonky chip chiller.

And yes, it is big. The RAM clearance is fine, as Noctua has engineered it to sweep away from dual-channel DIMM slots, but it's still going to take up a whole lot of space in your chassis. If you want to get the most out of it, you're also going to need some decent airflow in your case, too. Unless you're going for a completely fanless vibe, that is.

The Noctua NH-P1 is well-designed, impressively powerful passive cooler that could well keep your gaming PC quiet. Though it's not going to do anything for that noisy graphics card, I'm afraid.

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5. Corsair H60

All-in-one liquid cooling for the price of air


Type: Liquid cooling

Compatibility: Intel 115x, 2011/2066; AMD AM2-AM4

Fan speed: 600-1700 RPM

Noise volume: Up to 28.3 dBA

Dimensions: 157 x 120 x 52 mm

Weight: 1.32 lbs (600 g)

Reasons to buy

+ Excellent performance + Compatible with most cases 

Reasons to avoid

-Not as capable as double or triple radiators

Corsair was one of the first manufacturers to bring all-in-one liquid cooling to the masses. Nearly a decade after the company first launched its Hydro series, Corsair is once again leading the charge with the updated H60 as our top choice for liquid cooling on a budget.

Often priced $20 cheaper than our best high-end air cooler, the 120mm H60 offers nearly identical thermal and noise performance at a fraction of the cost. The updated cooler features a white LED illuminated pump head, 120mm radiator, and one of Corsair's latest 120mm PWM fans. Our tests put the performance of the new H60 far ahead of its other 120mm competitors and even in line with a few 140mm and 240mm coolers.

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6. Cooler Master Hyper 212 EVO

Longtime king of budget air cooling


Type: Fan and heatsink

Compatibility: Intel LGA 775 – 2066; AMD AM2 – AM3+, FM1 – FM3+, AM4

Fan speed: 600-2000 RPM

Noise volume: 9-36 dBA

Dimensions: 120 x 79.7 x 158.5 mm

Weight: 1.3 lbs (590 g)

Reasons to buy

+ Very affordable + Added AM4 compatibility 

Reasons to avoid

-Not as sleek as some

Cooler Master's budget-friendly Hyper 212 CPU cooler has been around for well over ten years now. With experience like that, it comes as no surprise that the newer Hyper 212 Evo has become a renowned pick for affordable performance. Priced around $30, the latest update to the Hyper 212 Evo features four direct contact heat pipes, an improved aluminum heatsink, and a 120mm high airflow fan.

From our testing, we found that the Hyper 212 Evo reduced CPU temperatures by up to 20 degrees celsius when compared to stock cooling. Another added benefit is that the cooler itself isn't a lot larger than a stock one, meaning it tends to stay out of the way of larger RAM modules. With such a low price point, we can't find any reason why we'd stick to a stock cooler over this. 

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7. Cooler Master MasterLiquid ML360R

A giant radiator for extra-quiet cooling


Type: Liquid cooling

Compatibility: Intel LGA2066, LGA2011 v3, LGA2011, LGA1151, LGA1150, LGA1156, LGA1155, LGA1366, AMD AM4, AM3+, AM3, AM2+, AM2, FM2+, FM2, FM1

Fan speed: 650-2000 RPM

Noise volume: 6-30 dBA

Dimensions: 394 x 119 x 27 mm

Weight: 5.6 lbs (2.56 kg)

Reasons to buy

+Stealthy CPU block logo+Affordable 360mm all-in-one solution

Reasons to avoid

-Not to everyone's taste

When you’re looking for the best liquid cooling options available, efficiency and effectiveness for heat dissipation are of utmost importance. The best way to approach this is to use a radiator with the largest surface area possible. For most modern mid-sized cases and full towers, this means a 360mm radiator. Equipped with three 120mm fans, these coolers take up quite a bit of space and can be relatively costly compared to a single 120mm liquid cooler.

Cooler Master’s 360mm MasterLiquid ML360R is our favorite choice. It features a beautiful CPU block design with a muted centerpiece logo, making for a spotless lighting setup. Combined with three addressable RGB fans, the ML360R cools well and runs quietly while providing some sexy lighting for your whole build.

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8. GamerStorm Deep Cool Assassin III

Best Budget big air cooler


Type: Fan and Heatsink

Compatibility: AM2, AM2+, AM3, AM3+, AM4, FM1, FM2, FM2+, LGA 2011, LGA 1150, LGA 1151, LGA 1155, LGA 1366, LGA 2011-v3, LGA 2066

Fan speed: 400-1400 RPM

Noise volume: 34.2 dBA

Dimensions: 165mm x 138mm x 25 mm

Weight: 3.2 lbs (1.45 kg)

Reasons to buy

+Thermal performance +Quiet+Price

Reasons to avoid

-Wide design

The GamerStorm Deepcool Assassin III may sound like someone’s terrible username, but it’s an impressively big air cooler. This wide boy houses twin cooling towers, seven heat pipes, and a pair of quiet 140mm fans. And with such large fans and plenty of cooling surfaces, this is an impressively performant air cooler too.

Silicon dreams

These are the current best CPUs for gaming to build your rig around.

For way less than $100, you can get yourself a quiet CPU cooler with exceptional thermal performance. Surprisingly, there’s no RGB lighting, making the Deepcool Assassin III a rather tame looking piece of hardware despite the flashy name. Though if you're chasing the more restrained aesthetic for your gaming machine, this quiet, stealthy chip chiller could be the dark horse of all our picks for best CPU cooler.

Best CPU cooler FAQ

How do you test CPU coolers?

Like most components, choosing the right CPU cooler depends on several variables, including performance requirements, case compatibility, budget restrictions, and aesthetics. To find the best CPU coolers, we test performance using Prime95 and a mixture of modern PC games for extensive stress testing. Our top selections were made based on thermal performance, noise, value, and overall feature sets.

How do I choose the CPU cooler that's right for me?

If you aren't sure whether you need an air cooler or a liquid cooler, it comes down to budget and compatibility. Until AMD released its Wraith coolers (and then took them away again), we'd never recommend a stock cooler to any PC gamer. Still, those on tight budgets now don't necessarily need to consider an aftermarket air cooler. If you have a little more spending room, liquid coolers can offer a whole lot more—from advanced RGB lighting to intelligent software control.

Some of you may be wary about putting liquid near your expensive components, but rest assured all of the coolers recommended in this guide are backed with excellent warranties that will cover you in the event of a manufacturer failure—a colossal leakage is an infrequent occurrence, anyways.

Is liquid cooling quieter than air cooling?

In general, an all-in-one liquid CPU cooler will be quieter than an air cooler mounted directly on top of the processor itself. That's because the fans attached to the cooling radiator are generally larger and can therefore spin slower than an air cooler. The water pump is often well insulated, so there isn't much noise from them either.

But there are large air coolers with big heatsinks and large fans that can compete well with the noise generation of an AIO liquid cooler. The quietest of all would be an entirely passive cooler, one with no moving parts whatsoever. However, those can't always cope with the most hot and heavy CPUs.

Do I need liquid cooling if I don't overclock my CPU?

Liquid cooling can undoubtedly give your processor the thermal headroom it needs to run comfortably overclocked, but there are other reasons you might want to have an AIO in your system. The vainest is the aesthetic—not having a huge hulking heatsink clogging up your chassis when there's a Perspex peephole to show off your components is often desirable.

That can also play into having a smaller chassis entirely. Liquid coolers can often give you the thermal performance to run a high-spec CPU in a small chassis where you'd only otherwise be able to fit a weaker, small form factor air cooler.

How does liquid cooling work anyway?

The coolant passes through a closed-loop via a plate that's attached to your CPU, and in combination with the attached radiator and fan, it cools the CPU. It's simple and a hundred times easier to install than an entire water-cooling loop.

Sours: https://www.pcgamer.com/best-cpu-coolers/
The BEST Cooling Solution - Air or Water - FINAL ANSWER

Best Liquid CPU Coolers 2021: Silent and Reliable AIO Liquid Coolers

Keeping your processor properly cooled is critical for getting the most performance possible out of it. While there are many CPU coolers to get the job done, few are as exciting as liquid coolers. Fortunately, you don't actually have to be some plumbing professional to set up a liquid cooler these days thanks to the proliferation of all-in-one (AIO) liquid coolers.

The AIO liquid coolers you'll find can actually be incredibly simple. They come with a water pump pre-installed with hoses that connect to a radiator, which can vary in size from a simple square 120mm way up to 240mm and even 360mm. They're even pre-filled with fluids, so you don't have to fuss around with any of that. In some ways, they can be even simpler to set up than an air cooler, as you don't need to carefully mount a heavy heat sink onto your processor.

The benefits of liquid coolers go further than that. They can also do a great job keeping your CPU chilled (just make sure you get one that is designed to handle the heat output of your processor), and can often do it more quietly than an air cooler. Plus, they can work better in tight spaces, such as mini ITX cases, since they don't have the same size constraints as air coolers that have to stick straight up from the CPU socket. So, if you're ready to dabble in liquid cooling, these are the best AIO liquid coolers to check out.

TL;DR – These are the Best Liquid CPU Coolers:

1. Corsair iCUE H100i RGB Pro XT

Best Liquid CPU Cooler

Corsair iCUE H100i RGB Pro XT
Corsair iCUE H100i RGB Pro XT

Corsair knows how to keep your processor cool, and the Corsair iCUE H100i RGB Pro XT is the AIO liquid cooler to do it. This 240mm setup is ready to handle some serious heat, so it’s no surprise that it comes with socket support for the latest AMD and Intel processors, including AMD’s Threadripper processors.

The Corsair iCUE H100i RGB Pro XT pulls heat away from your processor with a copper cold plate and pumps that into a 240mm radiator fitted with two Corsair ML Series 120mm fans. When temps are low, the fans can sit idle for silent operation, but when things heat up, they can kick into gear to push air through at up to 75CFM each while sticking to just 37dBA. The pump also can lend some style to your setup with 16 RGB LEDs on the pump head, and you can address each individually. Managing the AIO cooler is also simple. You can control fan and pump speeds from within Corsair’s iCUE software right on your PC, and monitor CPU temperature to make sure your settings are giving you optimal performance.

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2. Lian Li Galahad

Best Budget Liquid CPU Cooler

Lian Li Galahad

Lian Li isn't just making some of the best PC cases, and the Lian Li Galahad is a strong case for where else it can excel. This AIO cooler comes in at an affordable price while offering a sizable 240mm radiator and dual 120mm fans. Those fans feature stylish aRGB lighting that will let you customize the look of your PC, and the water pump housing also gets in on the light show.

The Lian Li Galahad fans can generate 2.79mmH2O of air pressure and 72CFM of airflow, sending plenty of air past the radiator to keep your CPU cool. The fans are rated to run for 40,000 hours and the pump is rated for 70,000 hours, ensuring you get every bit of value possible out of this cooler. Heck, Lian Li even includes thermal compound for the application so you don't need to spend extra picking that up.

3. Deepcool Captain 240 Pro V2

Best Ultra Cheap Liquid CPU Cooler

Deepcool Captain 240 Pro V2
Deepcool Captain 240 Pro V2

Looking for an all-in-one liquid cooler with a 240mm radiator? Want it to have RGB-lit fans? Want the pump to have RGB lighting as well? And you want it all for a low price? Lucky for you, you actually can get all that with the Deepcool Captain 240 Pro V2.

This AIO liquid cooler brings a bunch of the most exciting features at a low price point of just $100. You'll get your big radiator, and it'll include two fans with addressable RGB lighting. The water pump also has a light bar around the sides and an array of lighting on the top. All of that lighting can connect right to your motherboard for direct control and syncing with the rest of the system, or you can just use the included controls built into the cabling. The Deepcool Captain 240 Pro V2 is the complete package, and you can set it up with a wide variety of builds thanks to extensive socket compatibility, including AMD's AM4 and TR4 sockets and Intel's LGA20XX and LGA1200 sockets.

4. NZXT Kraken X53

Best 240mm Liquid CPU Cooler

NZXT Kraken X53

The NZXT Kraken X53 is the successor to our longtime favorite NZXT Kraken X52 that features some major improvements to look better and cool more efficiently. It comes fitted with Asetek's latest 7th generation, so you're getting the best flow and longest reliability compared to other cooler equipped with older water pumps. In our personal experience, we've seen this cooler have no problem keeping an Intel Core i7-9700K running well under 50-degrees celsius.

On top of all the cooling performance you get out of the NZXT Kraken X53, it still features the most unique looking infinity mirror lighting setup. Thanks to some optical trickery, this cooler can create seemingly unlimited rings of RGB lighting that go on forever. We've featured the 240mm X53 here, but the Kraken series is also available in all sorts of sizes from 120mm to 360mm.

5. EVGA CLC 280mm

Best 280mm Liquid CPU Cooler

EVGA CLC 280mm

Evga has recently been breaking into all kinds of new hardware territory and is a newcomer to the closed-loop cooling market. Still, the company knows how to craft some sweet hardware, and its new 280 CLC is one of the best bang for the buck models available. It utilizes a 280mm radiator with twin whisper-quiet fans, and also has beautifully designed LED integration on the water block.

Topping it all off is its killer software dubbed EVGA Flow Control, which allows you to control the fans, RGB lighting on the block, and the pump RPM as well. The pump is built with Asetek’s Gen5 pump technology, which is known for its reliability and efficiency. At around $115, the performance, noise, and quality are well worth it, and it is one of the best values in the market right now.

6. Corsair iCUE H150i Elite Capellix

Best 360mm Liquid CPU Cooler

Corsair iCUE H150i Elite Capellix
Corsair iCUE H150i Elite Capellix

If you want the most cooling potential, then you'll want a lot of fluid to sink your heat into. With a 360mm liquid cooler, you'll get just that. The Corsair iCUE H150i Elite Capellix can provide you with that cooling capacity and adds in a ton of style to top it off.

This 360mm offers impressive value given how large it is while still costing under $200. It's all the more impressive that Corsair throws in not one but four splashes of RGB lighting at this price. The water pump features a copper cold plate on the bottom for performance and 33 Capellix RGB lights on the top for fashion. The kit includes three 120mm Corsair ML RGB fans with eight RGB LEDs each. With that much light going on, you'll get tons of customization options for the style of your PC. The PWM fans allow for precisely controlled cooling with adjustable speeds from 400 to 2,400RPM as well as a Zero RPM mode for silent operation while the system is cool.

7. Cooler Master MasterLiquid ML240 Illusion

Best RGB Liquid CPU Cooler

Cooler Master MasterLiquid ML240 Illusion
Cooler Master MasterLiquid ML240 Illusion

RGB lights are fun on their own, but they get an extra special boost when paired with translucent material. That material basically turns into a glow stick when lit up, and then the RGB lights still get to cast their glow around the rest of your rig. So, when it comes to liquid CPU coolers, there’s a good reason the Cooler Master MasterLiquid ML240 Illusion stands out.

This cooler uses a translucent dome to house the dual-chamber water pump, letting the very heart of your motherboard shine brilliantly. Cooler Master also pairs the radiator with a duo of MasterFan MF120 Halo fans, which each feature a total of 24 ARGB LEDs to let you really customize the look. Naturally the fans also use translucent materials to push the light show to greater heights. Cooler Master even makes it easy to control the light show with an included ARGB controller so you won’t have to rely on your motherboard’s RGB hardware and software. You won’t miss out on strong cooling either, as the radiator has wide water channels to increase surface area and thereby the cooling potential, and the fans offer up 47.2 CFM of airflow and 1.6mmH2O of static pressure.

8. Alphacool Eisbaer Aurora

Best Refillable Liquid CPU Cooler

Alphacool Eisbaer Aurora

The Alphacool Eisbaer Aurora offers just about everything you could want in an AIO water cooler. It features a 240mm radiator to provide plenty of cooling performance, and the radiator is paired with two 120mm Aurora Lux Pro fans capable of 2.0 mmH2O of status pressure and 61.5 CFM of airflow. There's a healthy dose of RGB lighting on display here as well. Both fans offer rings of RGB lighting while the pump includes a transparent window with RGB lighting inside. And, of course, this cooler sets itself apart because you can refill the fluid inside to extend its useful lifespan. If you're interested in this one, you might have to wait a bit though, as stock has been scarce recently.

9. NZXT Kraken Z63

Best Liquid CPU Cooler with a Display

NZXT Kraken Z63

In the last couple of years, multiple manufacturers have tried to popularize liquid CPU coolers with screens embedded in them to varying success. But leave it to NZXT to perfect the idea with the gorgeous Kraken Z63.

Rather than just showing off rainbow circles in an infinite mirror, this flagship NZXT features an LCD screen you can use to show important information like your CPU and GPU temperatures. Alternatively, this little screen is also great for displaying completely unimportant things like animated GIFs. Aesthetics aside, this cooler comes equipped with a pair of strong 140mm fans and Asetek's latest water pump.

10. ekwb EK-AIO 240 D-RGB

Best High-Performance Liquid Cooler

ekwb EK-AIO 240 D-RGB

EKWaterBlocks has your high-performance gaming rig covered with its capable EK-AIO 240 D-RGB cooler. It's ready to use right out of the box on Intel and AMD systems, and it's compatible with the RGB control of many motherboards. Both of the included fans and the water block offer RGB lighting, so your rig won't just stay cool but will also look cool. The included Vardar S 120mm fans can produce 2.89 mmH2O of static pressure and 66 CFM airflow to ensure the 240mm radiator can consistently releases heat from your system. The hoses on this kit are especially flexible, letting you bend and fit them into even cramped cases while the nylon sleeve around each hose keeps it safe from damage.

Kevin Lee is IGN's Hardware and Roundups Editor. Follow him on Twitter @baggingspam

Sours: https://www.ign.com/articles/the-best-closed-loop-liquid-coolers-for-your-gaming-pc

Radiator cooler cpu

Offering a variety of models for every type of gamer, ASUS AIO coolers combine incredible performance to keep thermals in check, iconic designs, and the visual effects of Aura-enabled lighting, bringing next-level cooling and style to the heart of your build.

  • ROG

    Overclockers & extreme gamers


    Style-conscious gamers


    Casual gamers & first-time builders


With customizable visuals and top-quality fans that enable comprehensive coverage via air and water cooling, ROG flagship AIO coolers are designed to pair with today’s most powerful CPUs to deliver high-octane cooling with minimal noise.

  • Large Display

    ROG AIO series features a customizable LCD or OLED panel, which can be tuned to show system information or tailored graphics from center stage in your build.

  • Fans by Noctua*

    To overcome the thermal challenges of the latest CPUs and their unprecedented core counts, ROG AIO series offers industrial-grade Noctua radiator fans that deliver high performance and minimal-noise.

  • Pump-Embedded Fan*

    A 60 mm fan is embedded in the pump housing to ensure ample airflow to the CPU socket area. This fan circulates air to the CPU VRMs, M.2 slot, and surrounding components to reduce temperatures for added performance and stability.

*Only available for ROG Ryujin series

ROG Ryujin II 360

ROG Ryujin II 360

  • 3.5" LCD Display

  • Pump-embedded fan

  • Quality Noctua Industrial PPC PWM fans

Learn more

ROG Ryujin II 240

ROG Ryujin II 240

  • 3.5" LCD Display

  • Pump-embedded fan

  • Quality Noctua Industrial PPC PWM fans

Learn more

ROG Ryujin 360

ROG Ryujin 360

  • 1.77” color OLED

  • Pump-embedded fan

  • Quality Noctua Industrial PPC PWM fans

Learn more

ROG Ryujin 240

ROG Ryujin 240

  • 1.77” color OLED

  • Pump-embedded fan

  • Quality Noctua Industrial PPC PWM fans

Learn more

ROG Ryuo 240

ROG Ryuo 240

  • 1.77” color OLED

  • NCVM coating pump cover

  • ROG-designed radiator fans

Learn more

ROG Ryuo 120

ROG Ryuo 120

  • 1.77” color OLED

  • NCVM coating pump cover

  • ROG-designed radiator fan

Learn more

ROG Strix

Offering a range of sizes to choose from and extensively customizable aesthetics, ROG Strix LC series brings major cooling power to performance-intensive systems in various form factors.

ROG Strix
  • Innovative Cooling-Plate

    The advanced cooling plate on ROG Strix LC series is equipped with micro-channels that provide greater surface area to enhance thermal dissipation and reduce thermal resistance, delivering more efficient performance and cooler temperatures.

  • ROG Fans

    ROG radiator fans on ROG Strix LC series are specifically tuned to deliver optimum performance. And with 4-pin PWM control, both the pump and radiator fans can spin at slower speeds when the CPU is idling or under light load, helping to keep noise levels to a minimum.

  • Emanate Your Style

    Intricate designs on ROG Strix LC series showcase the iconic ROG aesthetic, and every detail shines with the spirit of Strix. For showing off your individual style, Aura-enabled lighting allows you to coordinate effects with ROG build components.

ROG Strix LC II 360 ARGB

ROG Strix LC II 360 ARGB

  • 7th gen Asetek pump

  • Addressable RGB LEDs

  • Six-year warranty

Learn more

ROG Strix LC II 280 ARGB

ROG Strix LC II 280 ARGB

  • 7th gen Asetek pump

  • Addressable RGB LEDs

  • Six-year warranty

Learn more

ROG Strix LC II 240 ARGB

ROG Strix LC II 240 ARGB

  • 7th gen Asetek pump

  • Addressable RGB LEDs

  • Six-year warranty

Learn more

ROG Strix LC II 360

ROG Strix LC II 360

  • 7th gen Asetek pump

  • Aura Sync

  • Six-year warranty

Learn more

ROG Strix LC II 240

ROG Strix LC II 240

  • 7th gen Asetek pump

  • Aura Sync

  • Six-year warranty

Learn more

ROG Strix LC 360 RGB

ROG Strix LC 360 RGB

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • NCVM-coating pump cover

Learn more

ROG Strix LC 240 RGB

ROG Strix LC 240 RGB

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • NCVM-coating pump cover

Learn more

ROG Strix LC 120 RGB

ROG Strix LC 120 RGB

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • NCVM-coating pump cover

Learn more

ROG Strix LC 360 RGB White Edition

ROG Strix LC 360 RGB White Edition

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • NCVM-coating pump cover

Learn more

ROG Strix LC 240 RGB White Edition

ROG Strix LC 240 RGB White Edition

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • NCVM-coating pump cover

Learn more

ROG Strix LC 360

ROG Strix LC 360

  • High-performance Asetek pump

  • Aura Sync

  • NCVM-coating pump cover

Learn more

ROG Strix LC 240

ROG Strix LC 240

  • High-performance Asetek pump

  • Aura Sync

  • NCVM-coating pump cover

Learn more



  • High-performance Asetek pump

  • Aura Sync

  • NCVM-coating pump cover

Learn more

TUF Gaming

The powerhouse AIO liquid CPU coolers in TUF Gaming LC series are designed for mid-sized gaming builds and feature a dynamic Asetek pump, a specialized fan-blade design, and aesthetics that can be tuned to your style.

TUF Gaming
  • Customizable Aesthetics

    TUF Gaming LC series coolers add a vibrant burst of color and sleek style to the heart of your build. And with Aura-enabled lighting, colors and effects can be customized to match your system, so you can create a unified look that's totally your own.

  • Optimized Fan Design

    Each radiator fan is specifically tuned to deliver optimum performance with TUF Gaming LC series radiators, and the fan blades are enhanced with a precision-engineered groove on the tip that improves airflow for reduced fan noise.

TUF Gaming LC 240 ARGB

TUF Gaming LC 240 ARGB

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • Six-year warranty

Learn more

TUF Gaming LC 120 ARGB

TUF Gaming LC 120 ARGB

  • High-performance Asetek pump

  • Addressable RGB LEDs

  • Six-year warranty

Learn more

TUF Gaming LC 240 RGB

TUF Gaming LC 240 RGB

  • High-performance Asetek pump

  • Aura Sync

  • NCVM-coating pump cover

Learn more

TUF Gaming LC 120 RGB

TUF Gaming LC 120 RGB

  • High-performance Asetek pump

  • Aura Sync

  • NCVM-coating pump cover

Learn more


ASUS AIO series coolers are compatible with a wide range of Intel® and AMD motherboard platforms, giving you the flexibility to pair them with your choice of processor. They also come fitted with 380 mm tubing to make mounting and routing easier.

CPU Socket Support

  • Intel®

    LGA 1150, 1151, 1152, 1155, 1156, 1200, 1366, 2011, 2011-3, 2066

  • AMD

    AM4, TR4/sTRX4*

    *the mounting bracket is bundled with a TR4/sTRX4 processor package.


Download PDF

Sours: https://www.asus.com/microsite/all-in-one-liquid-cooling/
Car Radiator CPU Passive Water Cooling - 汽車水冷器 主機被動水冷!

Best CPU Coolers 2021: AIO and Air Coolers

Best Closed-Loop Liquid CPU Coolers You Can Buy Today

1. CoolerMaster MasterLiquid ML360R RGB

Best 360mm Closed-Loop Liquid Cooler


Thickness: 1.1” (2.3" w/fans)

Width: 4.8" (120.7mm)

Depth: 15.5" (393.7mm)

Fans: (3) 120 x 25mm

Socket Support: Intel 2066, 2011x, 1366, 115x, 775, AMD AM2(+), AM3(+) AM4, FM1, FM2(+)

Warranty: 2 years

Reasons to buy

+Excellent cooling ability+Sleek design and aesthetics+Lower price than other 360 AIOs

Reasons to avoid

-Cable / controller management could be better

When it comes to keeping overclocked CPU load temperatures in check, Cooler Master’s MasterLiquid ML360R RGB is the new chilling champ. As the 360 variant of our previously reviewed MasterLiquid ML240R RGB, the newly available MasterLiquid ML360R adds 33 percent more radiator surface area for even more cooling prowess. The result? It cools even better than the mighty NZXT Kraken X72.

Power users, gamers, system builders and overclockers in the market for a new large CPU cooler should take note. The Cooler Master ML360R RGB is our current 360 AIO thermal performance leader. And while $160 isn’t exactly cheap, there are plenty of competing products that cost more while delivering less-impressive performance.

Read: CoolerMaster MasterLiquid ML360R RGB review

2. Alphacool Eisbaer Pro Aurora 360

Best 360mm Closed-Loop Liquid Cooler Alternative


Dimensions: 400 x 124 x 30/2mm

Pump Height: 2.25 inches / 57.2mm

Weight: 69.6 oz / 19748g

Fans: (3) 120 x 25mm

Socket Support: Intel 2066, 2011x, 3647, AMD AM4,TR4, sTRX4, sWRX8

Warranty: 2 years

Reasons to buy

+Threadripper cooling performance+G1/4 watercooling direct compatible+Dripless disconnects for simple expansion using Alphacool components

Reasons to avoid

-Could be quieter-Lacks software controls

The Alphacool Eisbaer Pro Aurora 360 features a full-cover CPU block sizable enough to fully cover Threadripper’s ample surface area, although it supports mainstream sockets like AM4 as well. There’s also a powerful, fast-flowing pump with built-in reservoir and an all-copper radiator, allowing the Eisbaer Pro Aurora 360 to morph into a custom cooling loop, one piece at a time.

Priced around $217, it's more costly than some other solutions, but does provide hands-down the absolute best cooling potential. And power users building high-end AMD Threadripper or Intel HEDT desktop workstation or gaming systems will have higher budgets, with a different focus than those looking for a more frugal desktop gaming or mainstream PC build.

Considering the cost associated with most of the CPUs and motherboards alone supported by the Eisbaer Pro Aurora, system builders in this realm of performance usually draw from a unique set of criteria, which a frequent aim for ‘the best at any price.' And that, quite simply, is what the Alphacool Eisbaer Pro Aurora 360 exemplifies. Whether you intend to run it as is, or expand into a custom cooling loop, you won't be let down by this versatile piece of cooling kit.

Read: Alphacool Eisbaer Pro Aurora 360 review 

3. Arctic Liquid Freezer II 280

Best 280mm Closed-Loop Liquid Cooler


Thickness: 1.5" (2.75" w/fans)

Width: 5.5" (139.7mm)

Depth: 12.5" (317.5mm)

Fans: (2) 140 x 25mm

Socket Support: Intel 2066, 2011x, 115x; AMD AM4

Warranty: 2 years

Reasons to buy

+Great cooling performance+Unique pump and auxiliary fan design+Low operational noise levels+Attractive price

Reasons to avoid

-Boxed unit ships with pump and fans managed by single PWM splitter-Lack of RGB lighting (for those looking for the option)

While our thermal measurements indicate that it's integrated voltage regulator fan is little more than a gimmick, great CPU temperatures at ultra-low noise levels prove the Liquid Freezer II 280 far-more-valuable than its far-costlier rivals.

Read: Arctic Liquid Freezer II 280 AIO review

4. Corsair H100i RGB PRO XT

Best 240mm Closed-Loop Liquid Cooler


Thickness: 1.0" (2.13" w/fans)

Width: 4.75" (120.7mm)

Depth: 10.9" (277mm)

Fans: (2) 120 x 25mm

Socket Support: Intel 2066, 2011x, 1366, 115x, AMD AM2(+), AM3(+) AM4, FM1, FM2(+), TR(X)4

Warranty: 5 years

Reasons to buy

+High-performing 240mm AIO cooling+iCUE software suite allows for customized cooler and lighting control+Priced well for premium performance

Reasons to avoid

-Noisy fans at 100% speed-Awkward, small screws used to secure fans to radiator-RGB lighting is pump-only

The Corsair H100i RGB PRO XT takes over where the H100i Pro left off by providing enthusiast levels of thermal load management from a 240mm AIO and making use of Corsair’s iCUE software suite for RGB lighting control, fan curve configuration and pump performance settings.  Paring the capability of the cooler with a set of user-friendly software tools provides a great deal of value for system builders of any technical proficiency, in real time. 

Read: Corsair H100i RGB Pro XT review

Best 240mm Closed-Loop Liquid Cooler Alternate: Deepcool Gamer Storm Captain 240 Pro

The Gamer Storm Captain 240 Pro makes up for in low noise what it lacks in cooling power compared to Corsair's H100i Pro, to the point that the Captain 240 Pro has a significantly better cooling-to-noise ratio.  We favor it for anyone who needs virtual silence at 50% fan speed, where most users in most environments won't hear it. Even those able to push a CPU hard enough to require 100% fan speed will find its hushed murmur less than half as noisy as the H100i Pro.

5. NZXT Kraken M22

Best 120mm Closed-Loop Liquid Cooler


Thickness: 1.1" (2.25" w/fans)

Width: 4.75" (120.7mm)

Depth: 6.15" (156.1mm)

Fans: (1) 120 x 25mm

Socket Support: Intel 2066, 2011x, 1366, 115x, AMD AM2(+), AM3(+) AM4, FM1, FM2(+)

Warranty: 6 years

Reasons to buy

+Great cooling for a compact AIO+Handsome, sleek design+CAM software is attractive &+intuitive

Reasons to avoid

-$99.99 price is higher than other 120mm AIO solutions-RGB controls only apply to CPU block face-CAM software sends data to NZXT cloud services

The NZXT Kraken M22 is an incredibly compact, high-performance liquid cooler that delivers sleek styling and vibrant RGB lighting options, while offering support for current AMD and Intel processor sockets. Specifically, if you're building a small home-theater PC or a compact gaming build, the Kraken M22 offers surprising cooling potential in a condensed cooling package.

Just don't try to strap one to your Threadripper system. The demanding thermals and massive surface of those high-end CPUs aren't supported by this cooler.

Read: NZXT Kraken M22 review

6. Enermax Liqtech 360 OC TR4

Best AMD Threadripper


Thickness: 1.125" (2.25" w/fans)

Width: 4.75" (120.65mm)

Depth: 15.50" (393.7mm)

Fans: (3) 120 x 25mm

Socket Support: AMD TR4, SP3

Warranty: 2 years

Reasons to buy

+Excellent cooling performance+Aggressive pricing+Easy installation+Full coverage of Threadripper CPUs

Reasons to avoid

-No software UI for real-time management-No RGB or LED lighting on fans (might be a plus, for some)

In the Liqtech 360 TR4 OC, Enermax has graced the Threadripper world with a cooler that covers these large enthusiast processors in full, providing performance similar to custom liquid cooling with the easy installation and moderate cost of an AIO cooler. Enermax also keeps costs down by avoiding RGB lighting and the relevant software integrations. The lack of lighting might turn away some buyers who prefer millions of colors and a software UI. However, Threadripper fans seeking excellent cooling performance, and who wish to set up some simple fan-cooling curves, will find just that in the Liqtech 360 TR4 OC.

Read: Enermax Liqtech 360 OC TR4 review

7. Alphacool Eisbaer Aurora 240 CPU Digital RGB

Best Reconfigurable Closed-Loop Cooler


Thickness: 2.25” (57.2mm)

Width: 4.88” (124mm)

Depth: 10.75” (273mm)

Fans: (2) 120 x 25mm

Socket Support: Intel 2066, 2011x, 1366, 115x, AMD AM2(+), AM3(+) AM4, FM1, FM2(+), TR4, C32, G34

Warranty: 2 years

Reasons to buy

+Quick disconnects for no-spill expansion+Solid thermal performance+Built with DC-LT pump and copper radiator water cooling components

Reasons to avoid

-Tubing length could be longer to allow for more diverse installations-Pump has coolant top-up port, but coolant must be purchased separately

Alphacool's Eisbaer is a factory-filled hybrid design, featuring a closed-loop-style pump and CPU cold plate with open-loop style fittings that including an anti-leak, in-line quick connector. Alphacool offers wide range of factory-filled companion parts, from additional radiators to GPU blocks, to suite nearly any expansion need. It's perfect for buyers who lack the time to assemble, purge, and leak test their own scratch-built component systems, as well as those who have more cash than self-confidence.

Read:Alphacool Eisbaer Aurora 240 CPU Digital RGB review

8. Alphacool Eissturm Hurricane Copper 45

Best Custom Cooling Kit


Thickness: 1.8” (45mm)

Width: 5.75” (146mm)

Depth: 18.5” (470mm)

Fans: (3) 140 x 25mm

Socket Support: Intel 2066, 2011x, 1366, 115x, 775, AMD AM2(+), AM3(+) AM4, FM1, FM2(+), TR4

Warranty: 2 years

Reasons to buy

+Great cooling performance+Professional-grade components+Very good value for a full watercooling kit

Reasons to avoid

-Pricey compared to AIO alternatives

With an enormous 3x 140mm radiator, this kit allows for enough thermal expansion of the loop to include a graphics card waterblock (or even two), if desired. By using industry standard G1/4 threaded fittings for all components, the cooling loop almost begs you to add more components to the party. A radiator of this size and potential allows for this kind of load because of the quality design and engineering that went into building it. A pump of this pedigree pushes coolant like few others are capable. Quality-milled components and attention to detail are seen on each and every piece within the kit.

For anyone looking for a complete, high-quality watercooling kit in a single box, this Alphacool Eissturm Hurricane Copper 45 kit is an excellent choice for those with room in their chassis for the monstrous 3x 140mm radiator and large pump/reservoir combo.

Read: Alphacool Eissturm Hurricane Copper 45 Review

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Matt began piling up computer experience as a child with his Mattel Aquarius. He built his first PC in the late 1990s and ventured into mild PC modding in the early 2000s. He’s spent the last decade covering emerging technology for Smithsonian, Popular Science, and Consumer Reports, while testing components and PCs for Computer Shopper and Digital Trends. When not writing about tech, he’s often walking—through the streets of New York, over the sheep-dotted hills of Scotland, or just at his treadmill desk at home in front of the 50-inch 4K HDR TV that serves as his PC monitor.
Sours: https://www.tomshardware.com/reviews/best-cpu-coolers,4181-2.html

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