Spreading Heat Sink Compound

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coius's picture
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I have been getting conflicting reports on how to do this, even my A+ Book doesn't give me exact directions on how to do it

What is the *BEST* way to apply this. I just bought a new Heatsink (all copper) and some Arctic Silver Ceramic-based Thermal Spread.
I want to know how to get the best out of this stuff. Every time I build a system for a client, either the component manufacturer tells you to apply a hell of a lot of the stuff (which doesn't seem as logical when you think of how it is just supposed to bridge the gap, not insulate it from the heat sink) or don't tell you anything.
I need to know this, as my System has been always running a bit hot, so I got a new heatsink am getting rid of that aluminum block on it) and got some spread to go with it off of newegg.com (both products)
Anyways, do i have to worry about sanding the pad on the heat sink? What is the best way to take off the old compound?

once I get this knowledge, it will help me build better systems. A site with visual pictures would help.

Remember, this system right now is running at 50 Deg C. when under full load. WAY TOO HOT for a Sempron. I have tried redoing it but don't think I am getting it right.

Also, the new fan/heatsink combo has more CFPM Air Movement than the last one (37cfpm vs. 22Cfpm.) and want to get the BEST cooling out of this.
Also, if you have seen my new case, it has already dropped the CPU Temp of the system down 4 Deg C already

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themike's picture
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I have always heard that it i

I have always heard that it is best to use only a very thin layer of the thermal compund.

I would think that to remove the old goop, if you were very careful a small putty knife would work well.

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Dr. Webster's picture
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To remove old thermal paste,

To remove old thermal paste, use a cotton swab moistened with isopropyl alcohol.

To apply fresh, do one of two things:

1. Put a drop of paste about the size of two grains of rice on the heatspreader of the CPU, then use a single-edge razor to spread it out. It should be a thin layer; the idea of thermal paste isn't to be the connection between the CPU and heatsink, but rather fill in the tiny pits in the metal surface.

2. Put a drop of paste on the CPU, then press the heatsink down firmly, and give it a slight twisting motion (to spread it around). The pressure of the heatsink should cause the paste to spread out, and if you put too much on it'll ooze out the sides. Not quite as elegant as using the razor blade, but if you do it enough you'll learn exactly how much paste to apply.

Or, if you're really paranoid/clumsy, places like Sidewinder Computers sells precut thermal pads that you just lay on the CPU, then install the heatsink.

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I like Dr Webster's tip about

I like Dr Webster's tip about using a single-edge razor to spread thermal paste. Good alternatives in my experience are craft knife/box cutter/Stanley knife blades, not in the handle/cutter, and chemistry lab spatulas. Blades are really effective for removing used thermal pads, but obvious care is required.

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Re: I like Dr Webster's tip about

charlieman wrote:

Blades are really effective for removing used thermal pads, but obvious care is required.

I wouldn't use a blade to remove any old thermal paste/pad; the risk of gouging the surface of the heatsink, or worse, the CPU heat spreader is too great. Isopropyl will loosen any thermal interface material really well, and it's perfectly safe to use since it's a non-corrosive agent. I suggested the blade for applying the paste because you use it in a pulling fashion, so you won't cut anything. It's using the blade like a putty knife that you don't want to do.

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IPA works great for getting t

IPA works great for getting thermal compound off. I've used it to get old stuff off of the P4 I used to build my newest Linux machine. The old stuff was stiff and cracked and tough silicone based and IPA softened it very quickly and it took a few passes but it wiped right off.

It also worked great to clean up and reapply some silver bearing paste I used for the P4 and the new heatsink, though I used an aluminum one. Most of the metallic ones are zinc and aluminum based, with a little silver thrown in. I don't know if that will cause much of a reaction, but the heatspreader of most CPUs ia aluminum, IIRC. I do know there are issues with mating aluminum to copper electriaclly, but I'm not sure how it effects heat transfer.

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TJH
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Isopropyl is definately the b

Isopropyl is definately the best for removal of old paste. For spreading I'd second the razor blade as that is how I've always done it. I've seen people just use a plastic bag over their finger for spreading, but when you pull the plastic bag off you'll remove a lot of the paste in the process, making it uneven and wasting a bunch. It does work for less precise jobs though.

coius's picture
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shoulda googled
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coius's picture
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well, got the heatsink

did everything right this time Laughing out loud
the system went from theose 50c down to 33c. almost a 20c drop!!!
also, they said the fan would be loud, but I didn't expect it to be THIS Loud
it sounds like a mini hoover vacuum Undecided

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Jon's picture
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How big is the fan and what's

How big is the fan and what's the RPM? I've got a CPU cooler that is at least 120MM and spins at just over 2400RPM. It's fairly nice and quiet. Plus, the PSU fan is thermally controlled (by the PSU), so it says quiet unless I start really pushing things.

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coius's picture
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7k rpm

and i don't know the size. it's about the size of an athlon CPU.
it supposedly moves 50CFPM of air

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coius's picture
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but then again

in this new case. the case has 4 fans of it's own. 2 front, 2 back. the power supply has a fan at the bottom, and a fan at the back (both lighted) and then the CPU has a fan. that's 7 fans altogether
I tell ya, it sounds like a wind tunnel to me, i wouldn't be able to tell the difference

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I too switched a while back f

I too switched a while back from aluminum HS to all copper and with my athlon xp1800 overclocked 400mhz, it sits under load at around 43c, down from 58c!! the fan on this thing is a little devil, i havnt yet gotten the nerve to buy an 80mm adapter, as its only a 60mm right now, which sounds to me like what you have. but all in all, copper is def the way to go, heavy and expensive but well worth it!

Ive got 80mm fan in front,120mm fan inside to blow air on chipset, 120mm fan in the bottom (case sits about 3/8" off the floor) PS fan is 92mm intake and 80 exhaust. the intake to exhaust ratio is way off so i leave a 5 1/4" bay open in the front and air screams out that thing so much that i have an air freshener and it works well! haha.

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7k is insane. I've got some

7k is insane. I've got some 1U servers that have CPU squirrel cage blowers that spin at 6500-7000RPM. It's a very annoying whine. If you increase the size of the fan it can spin at lower RPMs and still move the same air, plus the larger fan will blow over a larger section of the heat sink. One thing to check for in something you will be around a lot is the decibel rating. Find something that moves a good amount of air, but has a low decibel rating. Generally you can get a large fan to move a lot of air quietly, but a small fan can only move a lot of air loudly. One other thing to watch is interference of the air flow that causes turbulence and thus more noise. The holes stamped in a PSU fan mount typically still block a _lot_ of air. If you cut out the stamped section to have a round hole and use a wire finger guard you'll increase air flow and reduce noise.

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Have a look at this sucker: h

Have a look at this sucker: http://microcenter.com/byos/byos_single_product_results.phtml?product_id=234653

It's a 130mmfan w/ 120MM mounts. It spins at 1400RPM, and only makes 16dBA. Oh, and it moves 54.4CFM! Wink If I can find a 120MM mount int he case I have, I'm thinking I might like it. It's a sleeve bearing fan, but if some one knows of one that's dual BB with similar noise/flow specs, I'd be interesting in reading about it.

Drop a few fans like this in a case and you could rip out most of the other ones it's got. That'd keep the air flow up, but cut the noise significantly.

I do like the size and noise, but I'm disappointed by the bearings.

EDIT: Oooooohhh, ahhhhhh: http://microcenter.com/byos/byos_single_product_results.phtml?product_id=253410

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Dr. Webster's picture
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These are the only fans you'l

These are the only fans you'll need:

http://www.sidewindercomputers.com/paaxfa1.html

The best quality, quietest fans you can buy, period.

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