Liquid cooling is a radiator for the processors in a computer. Much like a car radiator, a liquid cooling system circulates a liquid through a heat sink attached to the processor. As the liquid flows through the heat sink, heat is transferred from the hot processor to the cooler liquid. The hot liquid then travels to a radiator at the back of the case and transfers the heat to the ambient air outside the case. The cooled liquid travels back through the system to the components to continue the process.

Over the years, CPUs (central processing units) and graphics cards have increased in speed. To achieve these new speeds, CPUs use more transistors, draw more power, operate at higher clock speeds, and therefore generate more heat than ever before. Liquid cooling is more efficient than traditional heatsink technology at moving heat away from components.

This technology, in turn, allows processors to run at higher speeds by keeping the CPU and graphics cards within the manufacturer's temperature specifications. This efficiency is one reason why extreme overclockers favor this approach, in some cases doubling processor speeds using highly complex liquid cooling setups.

Another advantage of liquid cooling is quieter operation. Most current heatsink and fan combinations generate a lot of noise because their fans work hard to move large amounts of air. Many high-performance CPUs even require fan speeds of over 5000 RPM; overclocking a CPU requires even more airflow over the CPU. Liquid cooling reduces the "motor noise" that this creates.