Do you know about this?

Overclocking is the process of forcing a computer component to run at a higher clock rate than it was designed for or was designated by the manufacturer, usually practiced by personal computer enthusiasts in order to increase the performance of their computers. Some of them purchase low-end computer components which they then overclock to higher speeds, or overclock high-end components to attain levels of performance beyond their factory defaults. Others overclock outdated components to keep pace with new system requirements, rather than purchasing new hardware products as expected by the computer industry.^[1]

Users who overclock their components mainly focus their efforts on processors, video cards, motherboard chipsets, and Random Access Memory (RAM). It is done through manipulating the CPU multiplier and the motherboard's front side bus (FSB) speed until a maximum stable operating frequency is reached. While the idea is simple, variation in the electrical and physical characteristics of computing systems complicates the process. CPU multipliers, bus dividers, voltages, thermal loads, cooling techniques and several other factors can affect it.

Considerations

There are several considerations when overclocking. The first consideration is to ensure that it is supplied with adequate power to operate at the new speed. However, supplying the power with improper settings or applying excessive voltage can permanently damage a component. Since tight tolerances are required for overclocking, only more expensive motherboards—with advanced settings that computer enthusiasts are likely to use—have built-in overclocking capabilities. Motherboards with fewer settings, such as those found in Original Equipment Manufacturer (OEM) systems, lack such features in order to eliminate the possibility of misconfiguration and cut down on the support costs and warranty claims to the manufacturer.

Cooling

Main article: Computer cooling

High quality heatsinks are often made of copper.

All electronic circuits discharge heat generated by the movement of electrons. As clock frequencies in digital circuits increase, the power dissipation goes up. Due to increased power produced by overclocked components, an effective cooling system is necessary to avoid damaging the hardware. In addition, digital circuits slow down at high temperatures due to changes in metal–oxide–semiconductor field-effect transistor (MOSFET) device characteristics. Wire resistance also increases slightly at higher temperatures, contributing to decreased circuit performance.

Because most stock cooling systems are designed for the amount of power produced during non-overclocked use, overclockers typically turn to more effective cooling solutions, such as powerful fans or heavy duty heatsinks. Size, shape, and material all influence the ability of a heatsink to dissipate heat. Efficient heatsinks are often made entirely of thermally conductive copper, but these are usually expensive.^[3] Aluminum is more widely used material for heatsinks, being cheaper than copper. Cast iron is the least expensive, but has poor thermal conductivity. Many good-quality heatsinks combine two or more materials to maximize thermal conductivity while minimizing cost.^[3]

Interior of a water cooled computer, showing CPU water block, tubing and pump

Water cooling and passive liquid coolant carrying waste heat to a radiator, which is similar to an automobile engine's cooling system, provide more effective cooling than heatsink and fan combinations when properly implemented, because liquid is denser than air and therefore offers greater thermal transference.

Thermoelectric cooling devices, also known as Peltier devices, are recently popular with the onset of high Thermal Design Power (TDP) processors made by Intel and AMD. Thermoelectric cooling devices create temperature differences between two plates by running an electric current through the plates. This method of cooling is highly effective but has a drawback that it leads to a lot of excess heat. For this reason, it is often necessary to supplement thermoelectric cooling devices with a convection-based heatsink or a water cooling system.

Liquid nitrogen may be used for cooling an overclocked system, when an extreme measure is needed.

Other cooling methods are forced convection and phase change cooling which is used in refrigerators. Liquid nitrogen, liquid helium and dry ice are used as coolants in extreme measures,^[4] such as record-setting attempts or one-off experiments rather than cooling an everyday system. These extreme methods are generally impractical in the long term, as they require refilling reservoirs of vaporizing coolant and condensation is formed on components due to difference between component temperature and air temperature.^[4] Moreover, silicon-based junction gate field-effect transistors (JFET) will degrade below temperatures of roughly 100 K (−173 °C/−280 °F) and eventually cease to function or "freeze out" at 40 K (−233 °C/−388 °F),^[5] so using extremely cold coolants may cause devices to fail.

Submersion cooling, used for Cray-2 supercomputer, involves sinking a part of computer system directly into a chilled liquid substance that is thermally conductive but sufficiently low in electrical conductivity. The advantage of this technique is that no condensation can form on components.^[6] A good submersion liquid is Fluorinert made by 3M, which is expensive and requires permits to purchase it. Another option is mineral oil, but any impurities like water or scenting agents might cause it to conduct electricity.^[6]