Overclocking is the process of running a computer component at a higher clock rate (more clock cycles per second)
than it was designed for or was specified by the manufacturer, usually practised by enthusiasts seeking an increase in the performance of their computers. Some purchase low-end computer components which they then overclock to higher clock rates, or overclock high-end components to attain levels of performance beyond the specified values. Others overclock outdated components to keep pace with new system requirements, rather than purchasing new hardware.
First we need to ensure that the component is supplied with adequate power to operate at the new clock rate. 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.
Cooling
All electronic circuits produce heat generated by the movement of electrical current.
As clock frequencies in digital circuits and voltage applied increase, the heat generated by components running at the higher performance levels also increases. The relationship between clock frequencies and Thermal design power (TDP) are linear. However, there is a limit to the maximum frequency which is called a "wall". To overcome this issue, overclockers raise the chip voltage to increase the overclocking potential. The relationship between chip voltage and TDP is exponential due to the fact that as the chip warms, the resistance lowers.
This increased heat requires effective cooling to avoid damaging the hardware. In addition, some digital circuits slow down at high temperatures due to changes in MOSFET device characteristics. 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, larger heatsinks, heat pipes and water cooling.
Size, shape, and material all influence the ability of a heatsink to dissipate heat. Efficient heatsinks are often made entirely of copper, which has high thermal conductivity, but is expensive. Aluminium is more widely used; it has poorer thermal conductivity, but is significantly cheaper than copper. Heat pipes are commonly used to improve conductivity. Many heatsinks combine two or more materials to achieve a balance between performance and cost.
Quality heatsinks are made of copper
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Water cooling
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Cooling with liquid nitrogen
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