# The best way to put thermal paste on CPU/GPU...



## intelligentsensory (Dec 19, 2011)

I have found that first rubbing a thin layer with my finger and then applying a second coat...smoothing it all using a razor blade is the best way to put thermal paste... one expert may say that putting thermal paste with the finger will transfer skin oil that will eventually affect the thermal transfer... but i can just say that i wash my hands first to get rid of the hand oil... further, just applying the thermal paste by a straight edge, will leave a honey comb layer... (i can provide facts) anyways.... what is your best method backed up by facts?


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## GunnyHighway (Sep 28, 2010)

For flat based heatsinks, dot in the middle, apply pressure. For HDT heatsinks I do three (or four depending on the model) lines along the aluminum spacers.

The problem with spreading it flat at the beginning means there's lots of ways for air to get stuck. The dot method isn't perfect, but by far the most simplistic and easiest method.


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## intelligentsensory (Dec 19, 2011)

> For flat based heatsinks, dot in the middle, apply pressure. For HDT heatsinks I do three (or four depending on the model) lines along the aluminum spacers.


 I really don't understand why there is much emphasis about the "middle" for a flat surface? I don't know what HDT heatsinks are but sounds like they are "ruffled"...


> The problem with spreading it flat at the beginning means there's lots of ways for air to get stuck. The dot method isn't perfect, but by far the most simplistic and easiest method.


 I really don't understand your definition of "spreading it flat"... in fact, I would guess that a "flat" layer of thermal paste is the main goal for best thermal transfer. You can do tests yourself... apply thermal paste with a knife or the tool that comes with the thermal paste and then compare the end results by using your finger to apply it... there will be a difference... with the knife or tool basically you are not getting in to the micro groves then if you whee to do it with your finger rubbing back and forth. Specially when the thermal paste is really thick... like artic silver 5.


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## offbyone (May 5, 2010)

The dot and push method distributes it evenly and minimizes air pockets which kill thermal conductivity. You also want to use as little as you can.


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## intelligentsensory (Dec 19, 2011)

^ i am not familiar with the dot and push method but i am sure that the main goal it so fill those micro groves with thermal paste... if you have ever caulked your bathroom or anything for that matter... the key to get in all the groves is to go forward and backwards more than twice... now if you use the dot method and push one way... that won't be 100% accurate because of the facts. also, i disagree with using as little as you can... what is the logic behind that? besides for the conductive thermal pastes (conductive = don't want to cause a short)


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## GunnyHighway (Sep 28, 2010)

It's because the thermal conductivity of thermal paste is far less than that of the metal in the heatsink (Copper and aluminum). You only want to use a bare minimum amount to cover the gaps where there is no possibility of direct metal to metal contact, hence the least amount of paste. 

I cracked open a PC at work the other day and found out they had used so much thermal paste that it actually caused the CPU to run hotter than it should have been.


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## intelligentsensory (Dec 19, 2011)

This whole thing had me curious that I did some tests... with two sheets of glass... I think I have already narrowed it to the best method... the traditional spreading the paste leaves bubbles... see here in this pic







and that makes sense. the dot and push (witch i just learned about) does leave air pockets, but very little







... but it does not cover the whole CPU surface area.... i tried to do a few dots and push but that was no good...







so the dot push is the winner in that it had very little, in some cases none, air pockets... but the problem still is that it does not cover the whole chip.


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## intelligentsensory (Dec 19, 2011)

> It's because the thermal conductivity of thermal paste is far less than that of the metal in the heatsink (Copper and aluminum). You only want to use a bare minimum amount to cover the gaps where there is no possibility of direct metal to metal contact, hence the least amount of paste.


 yeah but it does not matter if you use a lot because it will all be squeezed out by the screws. The only reason I would avoid too much squeeze out if I am using a thermal paste that can eat aluminum or components. Some pastes are just made for CPU with a copper heatsink... these supposedly are better heat conductors. So these regressive pastes, I would not want squeezing out on a capacitor ir resistor next to the CPU. But the silicone base pastes (the cheapest) cannot conduct electricity and nor are corrosive.


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## coldmorning (Jul 4, 2007)

Those are very impressive images. But I would guess a better test would be to check the temps on cpus using the different methods, no?


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## wjc75225 (Jul 24, 2010)

The dot method has worked best for me.


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## intelligentsensory (Dec 19, 2011)

> Those are very impressive images. But I would guess a better test would be to check the temps on cpus using the different methods, no?


 the end result for the best method is a combination of the BETTER tests... and it also depends on the BETTER thermal paste. Those images just explain pure science = truth. So there is not arguing about that... now it all comes down to the paste brand and how much/little to use. Example... I did a dot and push to my CPU yesterday and it runs hotter about 5 degrees... and before the dot and push I did the spread and push.... the difference is that I used a different brand thermal past... IOW, with a spread and push, using a different brand thermal paste, I was running cooler CPU than now with artic silver 5 with dot and push. So the winner would be the other brand with the spread and push. On my graphics card, I did the dot and push (removing the factory thermal paste) and now I am running about 10 degrees cooler which is good... lol... now I just need to test the dot and push on that thermal paste that gave me 5 degrees lower (on spread and push) and expect to get lower temps... but that paste is expensive (i paid about $23 dollars for about 12g of AS5 and $13 for about 4-5g of the other brand) and thicker than artic silver 5... lol... i'll order some though some time... i definitely want to test the dot on both my CPU and GPU with that brand.


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## intelligentsensory (Dec 19, 2011)

and interesting thing that i noticed, and probably makes sense, is that the dot method is giving me very stable temperatures. so i'm guessing there are no bubbles. with the spread method my temps where not as stable (jumpy, but average lower with a different paste like i mentioned above).... right now i am running prime95 (on max stressing), room temperature is about 83F degrees, and i am at a constant 76C....


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## offbyone (May 5, 2010)

There are tons of enthusiast sites out there that do extensive testing like this and compare all the different brands and types of thermal paste. I suggest you do a bit of googling if you want something more definitive.

Regarding the dot and push you actually don't need to cover the entire Heat spreader edge to edge to achieve good temps. Additionally many TIMs have a break in period so the earlier numbers are usually higher.

Here is a sampling of instructions:

http://www.arcticsilver.com/pdf/appmeth/int/vl/intel_app_method_vertical_line_v1.1.pdf
http://www.innovationcooling.com/applicationinstructions.html

I don't know anything about that diamond paste but I liked how it explained the thinking behind the dot and push.


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## intelligentsensory (Dec 19, 2011)

> you actually don't need to cover the entire Heat spreader edge


 i don't quite agree with that since the actual CPU metal part is a heat sink itself. that piece of metal is actually "glued" on top of the main chip/s (CPU/s)... do you have any reference to this?


> Additionally many TIMs have a break in period so the earlier numbers are usually higher.


 still, AS5 ends up loosing because i was getting 10 degrees lower from the get go with the other brand... right now, my CPU is at 48C at boot up.... with the other brand paste i was getting 10 degrees lower from the get go. IOW, if you are right, i would have gotten better results over time with that other paste. actually, now i see AS5 as a sore looser. what temperatures are you running from boot up?


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## intelligentsensory (Dec 19, 2011)

BTW, what do you mean by TIMs?


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## foofighter (Jan 2, 2012)

OP, you are intelligent for sure. i would suggest to not waste your time in teaching others.


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## mathman (Jan 20, 2009)

If you want to get really concerned about it, you have to lap the chips and heat sinks before application.


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