Sign in with
Sign up | Sign in
Your question

Heatsink grease: Over-apply -> over heat

Last response: in CPUs
Share
December 2, 2001 7:06:17 AM

I've discovered it's better to use too little thermal compound than to use too much. Apparently, if you have too much of the stuff, it will ooze out when the heat sink is clamped on. The excess goo will transfer heat from the die into the black sealant around the die, thus cycling heat back into the chip.

My CPU kept overheating (90-95 C!). I took off the heat sink, cleaned up the goop and reapplied it. But this time, I used a Q-tip with rubbing alcohol to clean around the edges of the die so that ABSOLUTELY NO compound was running off the edges. I even made sure the area covered by compound was a hair short of the edges of the die. Now my system runs at a comfortable 59.5 C.

I know some, if not most of you already knew this. I just thought I'd share the experience anyway...

-DOOM
"Ultimately, there is no knowledge -- only belief."
December 2, 2001 8:18:05 AM

indeed

if the base of your HSF is flat, then u only need the smallest amount.

i applied mine with a razor blade, a supremely thin coat.

they say half a grain of rice, but i bet mine was less than that.



Excuse me for a moment. I need to drive my ergonomic wheely chair over a sheet of bubble wrap!
December 2, 2001 8:37:51 AM

how did that happen? there is nothing hotter than the cpu so heat can only taken away from it.

<font color=blue>windows halted restart system.</font color=blue> <font color=red>me</font color=red> :mad:  . <font color=green>Bill G</font color=green> :lol:  .
Related resources
Anonymous
a b à CPUs
December 2, 2001 9:30:31 AM

Basicly, if it's over applied.. Instead of absorbing the heat, it reflects the heat back into the CPU.. When using Thermal Compound, I recomend using 1 mabye 2 pinhead drops of it.. Reason being, The surface is flat, so the smallest drop will spread through the entire surface from the pressure when it is clamped on..

And Good lord, If you ran @ 90c, are you sure you didn't damage your CPU???!!

Right now, I'm runing AMD Athlon 1700 XP @ 39c
December 2, 2001 9:54:48 AM

hmm. thats new to me. i'm going to try it out.

<font color=blue>windows halted. restart system.</font color=blue> <font color=red>me</font color=red> :mad:  . <font color=green>Bill G</font color=green> :lol:  .
December 2, 2001 10:23:18 AM

i knew something here was wrong. well i didn't see any difference, but on both THG and oc.com it says more is better. the other thing is even the sides of the die are hotter than the compound, thus heat can only be taken away. if you disagree with me you can check out THG.

<font color=blue>windows halted. restart system.</font color=blue> <font color=red>me</font color=red> :mad:  . <font color=green>Bill G</font color=green> :lol:  .
December 2, 2001 2:21:51 PM

I found that too much arctic silver II made my CPU heat up. When I lightened it, it worked.

But this doesn't quite make sense. ACII is basically silver, which is much more conductive than the die or copper of my HS. The contact was tight, and there was no spillage off the die. So even too much AC II should not have made the CPU heat up.

I have a theory. I have used AC II on several CPU setups and the results tend to be better after about 24 hrs. I think the liquid solution (don't know what it is) which holds the silver particles needs time to either evaporate or be squeezed out (and for the silver to congeal).

Anyone know what the solution is for AC II?
December 2, 2001 5:35:56 PM

All I know is:

Before - 90C
After - 59.5C

Before, I started up my system and let it sit in the BIOS power manager screen, and I watched the temp skyrocket. It started at 70. Bing, bing, bing: 71, 72, 73. 1-2 degrees per second. It only started slowing down after it reached 90.

After, when I reapplied a super light coating of the compound, I went back to the BIOS power manager, and the temp started at about 50, and slowly rose, 1 degree every minute until it hovered at 59.5. IT NEVER BROKE 60.

So whatever THG, oc.com, or the phantom heatsink faeries say, this is what worked for me.

Why do you suppose there was such a difference in my temperature if it wasn't related to the amount of heat sink compound?

(I am using Type 44 "synthetic ester base" compound)

-DOOM
"Ultimately, there is no knowledge -- only belief."
December 2, 2001 5:38:10 PM

Nope. A few times my alarm went off. I can't find a setting for the temp alarm, so I don't know what temperature it goes off at (prob 100).

So, yes, I may very well have damaged my CPU. Is there any way I can tell? Is there some kind of "hitpoints" meter for it? And where the hell are the med kits?

-DOOM
"Ultimately, there is no knowledge -- only belief."
December 2, 2001 6:06:42 PM

If it works you didnt damage it.


Too much heatsink compund acts as an insulator making the cpu overheat.

"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!
December 3, 2001 5:24:43 AM

hmm. i see well if it worked for you then i can't argue on that. cool.

<font color=red><b><i>you</i> keep talking i'll pretend i'm listening.</b></font color=red>
!