I have visited literally dozens of forums, web pages, and watched videos about applying thermal compound. I have seen people say "This is a good method." I've seen people say "No, you're doing it wrong" Visa versa, back and forth etc.... I'm going to use Arctic silver 5, but my question is, what is the best way to apply it? I've read, applying it with a credit card in a thin layer across the entire processor. I have also seen, putting a thin line in the center of the CPU and twisting your heatsink a bit to spread it out and then bolting it down and letting it take care of itself. Can anyone tell me which is better? Or a better method altogether?

From what I read, the second method I mentioned seems to work better, but I have a question about that. If you just put the compound in the middle of the processor and mount the heatsink, I don't see how the entire processor gets covered in thermal compund. To me, the 1st method seems better, because you're applying compound to the enitre processor (obviously making sure to not get compound where it doesn't belong).

Need clarification.

Salute~

Depends !! -- the best method to apply it will vary depending on the type of heatsink you are using (a flat surfaced Heatsink will be different than the direct contact heatpipe models, the amount of pressure the socket mount applies will vary, etc.) --- best thing to do is run a few tests to see which works best for your application and the specific parts\type of material you are using. What you want is a thin layer that covers the entire CPU (or almost all of it as the edges do not actually have any components that produce heat so missing a bit of the outer edges will not effect the temp) without having the material ooze off of the CPU (esp. if using a conductive material paste - since that excess could cause a short)

What you need to remember is the material itself is only for filling the microscopic flaws in the surface of the CPU and HS so that the 2 will have better surface contact - Not to create a layer between the 2 so you do not want a thick layer of paste just enough to cover the surface with a thin film.

When first assembling a system the best thing to do is test a few times using a couple methods and then removing the Heatsink to actually look at the coverage achieved until you find what gives the best result - Cleaning it off between each test. Then once you find a method that provides good coverage apply the final material using what worked best. (better to spend a few $'s testing than have poor results)

That is a very nice answer, thank you for the quick reply.

Over the past ten years of building pc's I have always used the credit card method. I have tried the little piece of rice amount in the middle and let the pressure spread out the compound, but I never felt that it covered the cpu as good as using the credit card method.

I think this comes down entirely to personal preference though.

This is exactly why I'm posting this question. I feel the same way.

Exactly -- and the materials are made to fill in the voids as needed so the thing that is most important is just that you apply the material in about the right amount (doesn't have to be exact) not how you apply it !!

Well the last time I did this (a couple of years ago now) I actually read the instructions for the Arctic Silver 5.
And they said put a tiny amount in the middle and then twist the heatsink to spread. But instructions may have changed.

I always place an amount the size of a pea in the center of the chip and then let the pressure of the heatsink spread it around. Works for me.

Put a pea sized blob in the centre of the CPU. Spread super thin with a credit card. Apply a little more paste if necessary.

When a nice even thin layer is achieved, mount the heatsink (without moving it round too much).

Done. I'm using Arctic Silver 5 paste myself, with an Arctic cooler fan cpu heatsink. Happy days.

Thanks guys, I think I'm gonna go old school on this though. I'm gonna get a latex, power-free glove, spread it and then thin it out with a card.

As JDFan said, it may have to do with the type of heatsink you have.
However, it also has to do with the type of CPU you have!

With the old Athlon XP CPU's, which didn't have a heat spreader (the metal plate which actually covers the CPU), the recommended method was to put a pea-sized amount of paste at the center and spread thinly and evenly with a credit card. This was very important to maximize heat transfer and because the heatsink pressure was not that great.

The method stayed very popular with the Athlon 64 and Pentium 4 generations (both of which have a heat spreader).

With the Core 2 Duo the method recommended by both Intel and Arctic Silver was to put a thin long line of paste through the length of the CPU (even though the heat spreader may look square, the CPU underneath is actually rectangular due to it being two CPU cores), then to NOT spread it manually and simply push the heatsink in place with a bit of twisting motion to ensure the paste would fill in the porosity in the surface of the heatsink base. This method is very effective in particular due to the immense pressure these heatsinks normally use (which sometimes even tends to warp the motherboard!).

By the way, I have been building systems for over 15 years, back in the days of the Pentium 2 and AMD's K6/2, and can't even remember how many times I have applied thermal paste to CPU's. I have also done plenty of overclocking. I can tell you that the recommended method for the Core 2 Duo really worked, as I was getting better temps than most people despite not using a high-end heatsink.

With quad core CPUs the method may be a bit different. Maybe they are now recommending the drop and credit card spread again?
I wouldn't know since I have never owned a quad core!

Look at this webpage, but be aware that your own results may be different from theirs. I still think you should search which method is best for your particular CPU:
http://www.hardwaresecrets.com/article/What-is-the-Best-Way-to-Apply-Thermal-Grease-Part-1/1303/1

Let's just go straight to the official recommendations shall we: http://www.arcticsilver.com/methods.html
Choose Intel or AMD.
End of discussion.

Edit: Short version:
1. Use credit card and tiny amount of compound and spread it to tint the surface. Then wipe it clean. (This is to reduce break-in period).
2. THEN apply a vertical line of compound and just mount the heatsink without twisting it.

I do a mixture of methods.
- Spread a super thin layer on the die surface.
- Tiny blob in the middle.

This way I know before I put the heatsink on the processor, it has got atleast some on the entire surface.
Then with that tiny blob, it will ensure any extra that is needed gets spread around.

As already mentioned, how the CPU and Heatsink is mounted and placed onto, will change your ideal methods.
This is the reason why I generally recommend a mixture of methods to be done. The worst that happens if you put too much on.

Just a quick pointer, to save lots of wasted time. If you are going to feck around and keep applying paste and then removing the heatsink to see how well it has covered, then you need to turn on the PC and run it under load for at least 24 hours after application to give the paste time to expand and fill all the gaps and then contract again after cooling.

It's no good putting the heatsink on and then taking it off to see how it has spread because it simply isn't giving you any usefull results.

My advice is to get some Microsi Shin Etsu G751 and put a small blob in the center of the cpu, then clamp the HSF in place and run the system under load. The heat and pressure will spread the compound into all the tiny gaps and surface imperfections far better than you could, with any implement you care to mention.

Why Shin etsu? It's what the people who make the cpu's use, it performs superbly after 24 hours or so of use, it does not " leak out " like so many other products do and in my experience it returns lower temps than all the " Top Brands " I have tried.