What happens if you use the WRONG amount of thermal paste?

How much thermal paste should you use? Today we find out!

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[RichardRichardman]

Just goes to show that if you're unsure, using more thermal paste than you think you need is better than using less than you think.

[Ishan.khanna]

The fact that a tiny amount of thermal paste prevents thermal shutdown was nuts to me

[Micharus]

Good experiment. Little or no filler, straight to the point with no mucking about. This would be really useful to someone who hasn't built a PC before.

[EnormousSmartass]

Chances are barely anybody will encounter this but there are super thick thermal pastes, which do yield worse temperatures when applied too thick! Specifically for instance the Phobya Nanogrease. In my tests the single best thermal paste outside of liquid metal and that stuff is so so thick, that you can't even use the blop method. However, when applied correctly awesome results and that explains (to me) why there's so much deviation between tests concerning this paste.

[HD]

Its better to use too much than too little. Especially when using open die but at that point i just spread it.

[ChloeASMR]

what would happen if you just decided to NOT put the paste onto the board and instead put it in your mouth?

[curve]

Thanks for this video. I always thought I really damage my motherboard and CPU actually just because a bit of thermal Paste in the socket but now I don‘t even think about it anymore so thank you very much!

[tempviduse]

Essentially you just need enough to cover the surface area (or the vast majority of it) in order to have even heat transfer. As long as you achieve that there isn’t much more to do

[malvolnc]

For all of you using liquid metal paste that is conductive you must completely disregard this video. any of it touching your motherboard will short it and fry your system immediately

[georgelewis]

Mechanical engineer here; I deal with all kinds of practical heat transfer problems daily.

This was a lot of testing with no explanation of the relevant heat transfer issues. The conclusion of too much paste not impairing cooling cannot be correct.

(1) Both the cooler and the chip surfaces have microscopic asperities, that in cross section look like an irregular sawtooth. Without thermal paste to eliminate the air gap, solid-to-solid contact is minimal, heat transfer is very inefficient and CPU temps will soar.
(2) In the analysis assume no air gaps (death for CPUs because gases are poor thermal conductors compared to liquids and solids).
(3) All heat transfer occurs by conduction through a chain, as follows: CPU --> Thermal Paste --> Copper base of CPU cooler. The copper in the CPU cooler has the lowest resistance to conduction of all the elements in the chain. The efficiency of the CPU cooler (more heat pipes, bigger fans and radiators) provides the temperature differential (or delta) that is the driving force for heat conduction from a warm body to a cooler body.
(4) The thermal paste has lower thermal conductivity than the copper, but whatever it is, having a thicker layer adds resistance to heat flow because the heat has farther to travel. That does not become noticeable (measurable) until a fairly large excess is used, as shown in this video.

My guideline is to spread a thin, semi-transparent layer using a razor blade, on both contacting surfaces. Seating the cooler properly on the CPU is crucial.

BTW, I saw a detailed study that found little or no differences between brands of thermal paste. However you probably want to avoid off-brand stuff from Temu.

[larryfarr]

Thank you. This is a great video for someone who is overly anxious about applying thermal paste!

[Interxoxo]

I accidentally put too much thermal paste on my acer nitro 5 and for the first week it was perfect but after it started getting more and more worse ending actually more worse than old thermal paste. It seems to me that at the beginning it is good because the paste is still in a condition like from the "packaging", but after use it starts to harden slightly, which causes hardening on the surface of the processor and the heat sink, and there is still a "packaging" consistency in between, which blocks the heat flow and keeps the heat between the heat sink and the processor (and its MORE LIKELY problem of processors without IHS like in laptops)

[jefferycoleman]

I spread a very thin smooth amount onto the cooler, then apply a small(rice) to medium(pea size) to the cpu. This works perfect everytime, good even coverage, little to no overflow, and pretty much dummy proof method.

[NONAME_]

I think using more and more won’t have an effect because the mounting pressure of the cpu cooler will be the same making the layer between cpu and cooler the same and just pushing more put to the sides

[SaidThoughts]

Just don't shoot the entire tube on the poor thing.

[aleksazunjic]

Thermal paste is used to fill in tiny cracks between two metal surfaces. It actually has worse thermal conductivity than pure metal-to-metal contact, but of course much better conductivity than air. Once the air is pushed out, any excess paste simply spills out and that is that.

[filipconstantin]

Very quick and comprehensive, just what I like when I want to get informed on a subject. Thanks!

[napoleon-skoc]

Thank you for demonstrating the parameters of application

[plantpalfynn]

this has been very interesting!, while it is kind of obvious that too much thermal paste can't lower the temperature below a certain point bc the fan can only get so much heat away it is nice to see that confirmed with an experiment. also thanks for adding the bit with the thermal past in the socket at the end bc again it's very reassuring to hear as someone who has rently build their first pc and is not sure if they did everything right

[JoeBob]

It would be interesting to see how this compares to making the top of the IHS, and the cooler plate, totally flat and smooth by sanding them down.
I mean, in reality a tiny amount of thermal paste (or none) should be just fine if both surfaces are totally flat. You just need more if your CPU has a convex or a concave shape.
When I apply thermal paste I generally like to wiggle the cooler around a lot on the CPU to make sure it gets to the right places.