TOO MUCH thermal compound?

Jun 14, 2003
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is too much thermal grease/compound bad?

i jus bought a new HSF the thermaltake volcano 9, and i have an AMD 2000xp

i smothered a layer of the stuff that cam with it across the chip, which looks smaller than imagined, then put a blob in the middle so that when the HSF was placed the blob spread out across the chip and the copper core on the v9.

so far its workin quite well, at full whack supposedly 4800rpm, (tho my mobo reckons its 5400rpm, and its an MSI which are quite good when it comes to sensing things) it keeps the chip nice and cool at 34 degrees C whilst idle, compared to the cheapo HSF i had b4 which kept the chip idling at 44-47 degrees.

ive never really changed a HSF before and i did have some help from my mate who knows a lot more than me about it, though he wasnt too sure either

have i done it about right?
 

HiTek21

Diamond Member
Jul 4, 2002
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What thermal compound are you using? If its artic silver all you need is a drop the size of a grain of rice and spread it around till the entire core is covered in a thin layer. If you mess up, wipe it off and try again.
 

jarsoffart

Golden Member
Jan 11, 2002
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You don't want too much thermal compoud. The best transfer is from metal-metal, but the heatsink bottom isn't always completely flat. It has many microscopic hills and valleys. The thermal compoud is only for filling in those gaps. metal-thermal compoud-metal transfer isn't as efficient as metal-metal. Some people also lap the bottom of their heatsinks so there are less hills and valleys, but I don't think you should lap the cpu die because that is supposedly laser cut, so theoretically it should be perfectly flat.
 
Jun 14, 2003
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well i used the stuff that came with it, its white, and probably really really cheapo stuff,
theres still a load left over, as i said befor, i put a thin layer on the cpu then a little blob in the middle so it would spread out across the sink and the cpu

by the way its already fitted and runnin quite well, it took a lot of effort to clip it to the motherboard coz so its nice n tight.

the stuff that was on before was like a sticker, and by the looks of it, things must have been hot, coz it looked as tho it had been bubbling!
 

HiTek21

Diamond Member
Jul 4, 2002
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If you want to knock of a few degrees from your CPU temps you may want to take jarsoffart's advice and lap the bottom of your heatsink and use some better Thermal compound. I use Artic Silver 3 but I hear that Shin Etsu Thermal compound is just as good or better than Artic Silver.

Lapping Guide
Shin Etsu or Artic Silver 3
 
Jun 14, 2003
10,442
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well i only do moddest overclocking and at the mo is cooling the chip to about 43 degrees in its slowest mode, bear in mind that the old hsf struggled to do this at full speed,

in full speed the idle temp is a full 10degrees cooler so i guess itll do for me.
if i get chance i may take it back off to wipe up a bit of the thermal stuff and maybe do that lapping thing.

so far its not got near a rather hot 55 degrees so it must be doing soemthing right.
but at a guess the way i done the thermal compound id say that its prob not workin a full 100% bout 90 ish. but as long as its cooler by a good margin it'll do.

thanks for the tips guys, ill bear them in mind next time :)
 

NokiaDude

Diamond Member
Oct 13, 2002
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You want a paper thin application. Remember, without grease, the CPU and Heatsink are "connected" together by the pressure of the clip. The AS3 fills in microscopic holes in the metal. Thus you need very little, or else it actually hurts your temps. But in your case the temps are normal.
 

Rhapsody

Member
Jan 1, 2000
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I have, perhaps falsely, been under the impression that a thin layer would develop if you put a modest amount and then, when the clip is attached, move the heatsink back and forth a bit against the CPU. Any comments?
 
Jan 31, 2002
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Originally posted by: Rhapsody
I have, perhaps falsely, been under the impression that a thin layer would develop if you put a modest amount and then, when the clip is attached, move the heatsink back and forth a bit against the CPU. Any comments?

Oh dear god no. :Q

Read, and read well.

- M4H
 

1313

Senior member
Jun 29, 2002
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I think the best approach is to clean the heatsink and core with 99% pure isopropyl alcohol*and some sort of lint free wipe. Everthing must be clean since the goal is to not contaminate the compound, or surfaces, with anything that could affect heat transfer

And then apply a very thin and even coat of your favorite thermal compound.

I found that gently squeezing the syringe so that the compound has only started to come out and then dabbing the core or heatsink with the compound and leaving many small dots all over the makes it easier to get a thin coating.

Sometimes warming the compound helps [like with Shin Etsu G751] and the compound can be spread with a credit card, razor blade, or finger inside a baggie. Even the oil on your finger could hurt performance, as could dust or any contaminant like dead skin or hair.

The compound can be applied to the core or to the heatsink. If applied to the heatsink, then masking the area with a non residue tape will make precise application easier.

Then clean up the excess with a clean wipe and alcohol.

Rough heatsinks, uneven cores and cores with shims, could benefit from lapping or from a thicker compound that will allow some fill-in and stay put.

Some of the concerns about various thermal interface materials are electrical conductivity or capacitance, and thermal pumpout. This is probably why manufacturers like thermal pads and are not found of most of the thermal pastes that perform well.

I think that they are concerned that with higher temperature cores the pastes will flow out of the heatsink/ core interface over time and risk overheating the core








*[ 70% isopropyl is much easier to find, but it probably has some oils in it that may affect the thermal compound's performance]

 

pspada

Platinum Member
Dec 23, 2002
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Originally posted by: MercenaryForHire
Originally posted by: Rhapsody
I have, perhaps falsely, been under the impression that a thin layer would develop if you put a modest amount and then, when the clip is attached, move the heatsink back and forth a bit against the CPU. Any comments?

Oh dear god no. :Q

Read, and read well.

- M4H

My EXACT thought ^