The Thermal Paste

The thermal paste is basically composed of silicone and zinc oxide, but there are more elaborate pastes that can even contain ceramic and silver – noble materials that promise more efficiency in heat transmission.

Its price can range between USD 2 and USD 32 (in pastes that have silver in their composition).

Thermal paste can be found in many kinds of packages and usually comes with the cooler. Figure 3 shows many kinds of packages.

Thermal GreaseFigure 3: Many kinds of thermal pastes

There are also coolers which have some material applied from the factory. In addition, coolers that come with the processor (“in-a-box”), or even some coolers sold alone, are found on the market with thermal paste already applied.

In the case of coolers that come with the processor and coolers of recognized brands, the quality of the material applied is usually good, and both AMD and Intel recommend the use of those compounds.

Thermal GreaseFigure 4: Cooler in-a-box for Pentium 4 with pre-applied thermal paste

Thermal GreaseFigure 5: Cooler in-a-box for Athlon 64 with pre-applied thermal paste

Thermal GreaseFigure 6: Cooler in-a-box for AMD socket 462 processors with pre-applied thermal paste

All of the above compounds are of good quality and have better efficiency than regular thermal pastes. If you bought a super thermal paste containing silver, you should remove the original compound and apply the new paste instead.

Unfortunately, the use of those compounds “from the factory” has some inconveniences. The first one is that they can be used only once. If you remove the cooler for some reason, you’ll have to clean the old compound and apply the original one again (which is hard to find) or apply thermal paste instead. Another very common problem is that the compound ends up sticking the heatsink to the processor, making cooler removal difficult.

In the case of Intel socket 478 and AMD sockets 754 or 939 processors, it’s very common to pull the cooler and take out the processor at the same time if it is stuck on the heatsink, something that ends up damaging the processor in most cases. The tip here is to use a hairdryer to heat the heatsink a little in order to melt the thermal compound and then remove the heatsink with lateral movements. But don’t use the hairdryer too much.

There are also cheaper coolers that come with a graphite square or thermal tape similar to gum that are terrible heat conductors. In this case, you should remove those compounds and apply thermal paste instead.

Thermal GreaseFigure 7: Cooler for Socket 7 with graphite compound you should remove

Many people believe that the more thermal paste, the better. A lot of paste turns out to be insulating, not to mention that paste in excess ends up dropping down and reaching motherboard contacts. Remember that most pastes don’t conduct electricity, but there are pastes that contain metal in their composition which turns them into conductors that may cause a short circuit and destroy your equipment.

We will show in detail how to apply thermal paste on several kinds of processors.

Daniel Barros lives in Brazil and used to be our motherboard reviewer. He is a partner at a local PC sales and maintenance store.