I searched this subject and found this thread. I thought I would start a new thread instead of posting in that one, because I’d like some clarification.
I bought Tiggrkitty an AMD Athlon 64 4200+ X2 retail, boxed processor. Now, the linked thread says that the pad on the underside of the heatsink is the thermal pad. When I looked at it, I figured that’s what it was, but I wasn’t 100% sure, because really, it didn’t look like it would be much help. So, I picked up some thermal paste from work.
Now, her computer is mostly assembled (we’re waiting on the memory to come in). When I was installing the processor, I applied the paste and spread it out so there’s a very thin layer on the processor. I just don’t know if it’s enough.
So, my question is, what IS enough? I know I don’t want so much that it’s oozing out of the sides. Do I want some excess in there? Or is the amount I already applied enough with the pad that’s on there?
I’d have to look at the install instructions that came with that processor, but, generally, if there’s a pad on the AMD retail boxed heatsinks, they don’t recommend adding anything else at all.
Agreed. I have an AMD Athlon 64 and it came with a thermal pad already on the base of the CPU. It’s running cool enough with just that thermal pad. I don’t have any numbers handy, but I’ve checked it through the BIOS before and the numbers are good, definitely less than 100 degrees.
I agree with the others, use the pad. The pad supplied with the heatsink is sufficiant for most CPUs (unless you overclock) for one use. The first time you use the computer the pad will melt around the CPU, so if you ever remove the heatsink you’ll have to replace the thermal paste.
However, it sounds like you’ve already put thermal paste on the CPU. In that case, you DO NOT want to use the pad and additional thermal paste, that would be too much. If you’ve already added additional thermal paste to the CPU then you need to remove the pad on the heatsink. The easiest way to do this is with some goo gone, but if you don’t have any, then just use some windex and a paper towel. Clean off the entire pad from the underside of the heatsink, let it dry, and then put the heatsink on the CPU.
As for how much thermal paste to use? When I was setting up motherboard/CPU combos on an Athlon 64, I used to make an X with the thermal paste. When you mounted the heatsink it would smoosh the thermal paste to a nice even coating.
Just be warned, too much or too little thermal paste will cause the CPU to get hotter then it is suppost to be. Once the computer has been on for a little while, check the CPU temp in the BIOS. It should be BELOW 70 degrees Celcius.
Hey that was my thread and I’ve learned a few things since then…
Mixing the paste and the pad is a very,very bad idea. Just use the pad (if it has paste on it now, it’s probably ruined) or scrape it off, clean the heatsink and processor and reapply the paste. Be careful.
After I posted the above, it turned out the barebones I was building was DOA. I ended up taking the CPU/heatsink out, cleaning them well and applying a new pad before putting them in a new board. The system’s been running under load (in a small form factor box) for days without any heat issues.
Okay. I took the heatsink off the processor, and either I was hallucinating before, or the thermal paste ate the pad that was on the processor. It’s not there anymore.
Anyway, I was able to get all of the paste off of both the heatsink and processor. This is what I need, correct?
Just to clarify, the thermal interface material is only there to span gaps or to fill manufacturing/machining imperfections in the interface between the processor case and the underside of the heatsink. In virtually all scenarios the TIM has a higher coeffecient of thermal resistance than either the case or the heatsink - that’s why some overclockers sand/polish to a mirror finish and/or precisely match the CPU to the heatsink. Therefore, when using pastes you’ve received the guidance to use as little as possible whilst still completely covering the CPU/heatsink gap. Thermal pads are a compromise, in that they have generally better gap-spanning properties and are much neater, but often have higher thermal resistance than pastes. There are even phase-change materials that have some of the advantages of both pastes and pads. Hope this is useful - I apologize if you already had all of this.