- Date:
- Tuesday , April 07, 2009
- Author:
- Marc Adams
- Editor:
- Kyle Bennett
- Share:

Thermal Paste Shootout - Q209
We take 10 high profile thermal pastes used for mating heatsink surfaces to CPUs and other components and subject those to over 1200 hours of testing to find out which one reigns supreme. Drop or spread? And we tried American cheese too, just in case you find yourself in a pinch.
Applying the paste
There is an ongoing debate about the best method for applying thermal paste to your CPU. This issue is further complicated by manufacturers listing different methods for their pastes. The two most popular methods are to place a pea sized drop at the center of your CPU and let the pressure from the heat sink spread it out or to apply a thin even layer across your CPU ensuring maximum coverage.
Both methods have their pros and cons and we will test each of the pastes in both methods to see if there is one universal method for applying thermal paste or is it a case by case basis.
First take a look at this flash movie developed by MG Chemicals. It shows in no uncertain terms how to apply thermal paste when using the full coverage method. Often times I find people apply to much paste thinking if some is good more must be better.
It is important to remember that thermal paste is only used to fill gaps of air which conduct heat very poorly. Metal, on the other hand, conducts heat much better so we should be careful not to interfere with the metal on metal contact we desire.
Let’s take a look at how each paste performs when using the different methods of application. For this test we apply each paste by placing a pea sized drop in the center of the CPU and allow the pressure from the heat sink to spread it out. We then boot up into our OS and run Prime95 for fifteen minutes to get a temperature reading. We then clean the CPU thoroughly and apply the same paste in a thin, uniform layer across the entire processor and repeat the test.

It would seem the confusion over the best way to apply thermal paste has some merit. Various pastes respond differently to the different application methods.
If I had to explain the differences it would come down to viscosity. Every paste the performed better when using the pea drop method has a thinner consistency that spreads easily. The pastes that performed better using the thin layer were all thicker and thus required extra help to spread evenly that the heat sink could not provide.

