Heat sink paste is a dense compound material used to improve the contact between electronic components such as CPUs and their cooling mechanisms. The primary function of this material is to facilitate the transfer of heat from the CPU to its cooling mechanism, reducing the CPU’s temperature, which in turn prolongs its life and performance.

The contact surfaces between a CPU and its heat sink have many microscopic scratches and imperfections that trap pockets of air – air is one of the worst thermal conductors on Earth, impeding the CPU’s ability to dissipate the maximum amount of heat. A properly applied and spread layer of thermal paste reduces these gaps, increasing the useful surface area for heat dissipation.

When choosing a thermal paste, there are many options to choose from. Silicone and non-silicone based products are available, with the latter often being chosen for a more stable and less volatile formula that does not migrate to unintended areas or damage the motherboard during assembly. Those who prefer a more metallic experience can opt for metal-based thermal pastes, which vary in their thermal conductivity depending on the ingredient; silver is one of the most popular.

Once the thermal paste has been selected, it should be applied to the CPU in a pea-sized dot and allowed to settle. This can be done with the aid of an applicator, though it is recommended to let the pressure from the heat sink or water block being installed do this for you – attempting to manually spread the thermal paste will result in air bubbles, which will diminish its effectiveness.