Thermal paste fills the microscopic gaps and interstices between a CPU’s integrated heat spreader (or IHS) and the base plate of its heat sink to improve the transfer of heat from one surface to another. It is an essential component of modern PCs, preventing overheating and sudden shutdowns. The best thermal pastes are creamy or liquid, and they also have the ability to fill small air pockets, reducing the transfer of heat from the processor to the heat sink by creating an air-tight seal.

In order to achieve the most effective performance, it is crucial that you apply thermal paste correctly. The first step is to clean the surfaces of the processor and the heat sink with a coffee filter or lint-free cloth and isopropyl alcohol (IPA, 90% concentration). Then, place a small dab of thermal paste, which Maximum PC recommends be no larger than a pea, on the top center of the processor. Once the dab is placed, lower the heat sink’s connecting part flat against the processor. The pressure of the heat sink will then spread the thermal paste across the surface.

The best thermal pastes will not only perform well, but they will be easy to spread and won’t leak. They will also be electrically insulative, which prevents them from transferring electricity between the surface of the processor and other components in your computer. The most popular and well-known brands of thermal paste are sold in tubes and are typically priced between $3 and $10 USD.