Cpu cooling is a method used to keep computer components at a safe operating level of heat. This is accomplished through both integral (built into the component) and peripheral means.
Cooling is necessary because computer components gain heat when they operate, and that heat must be dissipated to prevent performance degradation and damage. This can include [[integrated circuit|CPU]]s and [[graphics processing unit|GPU]], as well as [[hard disk drive|hard drives]]. Generally speaking, these electronics will only operate safely at a temperature that is below a certain maximum permissible value which is unique to each component.
Early computers, such as the vacuum-tube machines of the 1950s, relied on natural or forced air circulation to help cool their active components. As solid-state electronics became more commonplace, cooling methods had to become increasingly sophisticated to ensure reliable operation.
One common method involves passive heatsinks, which entail clamping a block of machined or extruded metal directly over the component that requires cooling, with a thermal adhesive applied between. Then thin metal fins, often with ridges and nooks, are arranged on the surface of this block to increase the area exposed to cooler ambient air. An attached fan then blows the air away from the component, dispersing its heat into the surrounding environment.
Another method involves liquid cooling, in which a reservoir of liquid absorbs and dissipates the excess heat. Many different types of liquid can be used, including mineral oil, water and various single- and multi-phase synthetic or dielectric coolants. The latter typically have low electrical conductivity, so they do not interfere with the normal operation of the computer.