Is Thermal Paste Needed?

morrow58

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Apr 29, 2017
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When installing a new CPU, do I still need to apply fresh Thermal Paste to the new CPU when the new heat sink cooler already has some pre-applied?
 
Solution
That would be a bad idea.

1) You don't want to mix thermal compounds, as it is unclear how they would interact
2) The amount required is as little as possible to fill small gaps between the CPU heat spreader and CPU cooler. More is actually worse and begins to act as an insulator.

If you want to use your own compound, completely clean the pre-applied compound with isopropyl alcohol and a lint free cloth (heavy duty paper towels, cotton swabs or pads, or coffee filters are popular choices as well)
That would be a bad idea.

1) You don't want to mix thermal compounds, as it is unclear how they would interact
2) The amount required is as little as possible to fill small gaps between the CPU heat spreader and CPU cooler. More is actually worse and begins to act as an insulator.

If you want to use your own compound, completely clean the pre-applied compound with isopropyl alcohol and a lint free cloth (heavy duty paper towels, cotton swabs or pads, or coffee filters are popular choices as well)
 
Solution


Yes, but this would not be beneficial. The presumption of pre-applied paste is it's the necessary amount, and therefore any additional paste you're adding is excessive and actually decreases the heat dissipation performance. You'd want to generally use less paste than more.

If you have a CPU and heatsink with no paste on either (I know this isn't your exact situation), a good rule of thumb is to apply a small bead of paste the size of a grain of rice on the CPU. Don't spread it. Then seat the heatsink on top of the CPU and tighten into place allowing the pressure to naturally distribute the paste.
 
Not sure on the downvote, you made pretty much the same points and then added the common instructions for applying thermal compound.

As for the amount to apply, it really varies on the heatsink in question. Ones with a polished or plated base need very little, like the grain of rice. Machined surfaces a little more, and things like direct contact heatpipes, significantly more as they tend to have large gaps between each pipe that need filling. On direct contact heatpipes I often do an installation, remove, clean and reapply to make sure the spread is good and to fill in all the little gaps.