Going from AS3 to thermal pad = 7°C drop in temps

[Mark Larson]

Atleast that's what my amateur setup tells me in my personal system.
I've applied a fair bit of thermal grease myself, starting from normal white goop and going onto the rocket-science AS3 stuff. Got good temps, thought everything was fine.

Then i read about TIM and why it was better for long-term applications and suchlike. Well, i thought, why not try it out? I ordered some as a sample from a well-known company and it arrived neatly packaged.
I ripped out my AX-7, cleaned off both the CPU and HSF bottom with acetone, and applied the thermal pad as they instructed.
Got better temps, but didn't think much. This was back in Jan `03.

Then i got a watercooling setup, with a Maze2, Maxijet 1200 and heatercore and a 10gal res. I used AS3 and wasn't happy with the temps. I waited a week, reapplied, still the same.

Then today i decided to try the thermal pad. I thought, "well, if it worked on my AX-7 it should work here".

Took the block off, cleaned everything off with a lot of acetone (don't do this in an ill-ventilated area, kids!) and applied the TIM. Put everything back together, and fired up the system without the pump running. Watched the temps get up to 44...prime crashed. 48....Windows crashed.

Get into BIOS and watch the temps climb to 55°C. Switch on pump and watch temps fall. Restart at 41°C.

All this was about 4 hours ago. I believe i've given enough time for the water temp to stabilize. I'm running at 34°C right now. My earlier temp used to be 40-42°C on average, more in the morning when the windows had been closed all night.

I'm a firm believer of TIM now, and my AS3 will be relegated to the cupboard, only for emergencies when a TIM is not available, not worth the trouble of cleaning up, or just too precious to be used.

I will look at AS3 fanboys online and nod my head sagely and hit backspace. The damage to the thread has been done and i won't bother with it.

Chalk it up to whatever - maybe i'm bad at applying AS3, maybe the Arctic Gods don't like me, maybe its been a fluke all these times. But i believe. I believe in the TIM. I will always use TIM. TIM is my lover and i want to have its children.

SETUP:
1700+ Tbred at 2600+ (166x12.5) 1.750v
EP-8RDA
Maze2
5.5"x7.5" surface area heatercore without fan
Maxijet 1200
10gal res with pump submerged
Everything connected with ½" vinyl tubing.

Take this post in jest or take it seriously. My writing style may invite jeers but my gains are real.

Mirror: http://iupload.net/042003/tempreduction.png (Copy and Paste - clicking won't work)

BTW this is no joke.

 

[Defcon3X]

Wow, thats really strange, I always thought that AC3 was the best that you could use. Can you post a link to this thermal pad that you talk of?

 

[majkmil]

whats TIM?

 

[jlin453]

yeah, some info would be helpful

 

[I.M.O.G.]

whats TIM?

Thermal interface material.

If you do a forum search you will find more information.

 

[Daemonfly]

I'm wondering if the mounting pressure, etc.. were the same for both AS3 and the thermal pad.

 

[Mark Larson]

I'm wondering if the mounting pressure, etc.. were the same for both AS3 and the thermal pad.

Everything was the same - in the first application i didn't use washers, and in the second one i did. I also used washers with the TIM so the conditions were the same.

(BTW, i think i got like 1-2°C reduction from increasing the mounting pressure with washers in the second application of AS3 - that is too little to be able to attribute to any specific factor though)

 

[Spartacus51]

Except that AS3 is technically a TIM. TIM - thermal interface material. There are numerous factors that could be affecting your temperatures. The most likely of which is that your tube of AS3 is not AS3 at all, more likely a cheap imitation marketed as AS3. Try a new tube of AS3 and post your results, I have a feeling you'll find that pad does not perform as well as the AS3.

 

[grunjee]

You may have had too much AS3. Recently I was wondering why my temps were bad... so I removed my block. I shaved down the AS3 and to my surprise, my temps went down 11° C.

 

[FIZZ3]

Objectively speaking I don't think it is even possible for two TIMs like Arctic Silver and an Undefined Thermal Pad to differ so much in their thermal properties to make a real 8C difference.

Numerous tests have also shown that pretty much any thermal grease outperforms thermal pads, with recent pads doing better but still playing catch up. Maybe the differences between the latest products and thermal grease are minimal, but the pads are unlikely to outperform the grease (especially as3, widely regarded as one of the if not the top grease). Such a huge margin makes it doubly strange. Just my 2c.

 

[TheMightyBuck]

so yeah... tell us where u got these thermal pads.. i'm gonna get some and use their voodoo magic to get below ambient temps with them..

then i'll call up Miss Cleo and she'll get my temps to -3 C with thermal pads...

(all in good fun)

seriously, what brand thermal pads did this for ya? you've made me curious enough to try 'em.

 

[HeXenViRii]

It could boil down to the TIM pad just being able to give more contact area between the WB and the cpu . I know that when i attach my WB and use AS3 i sometimes have to lift it up a little or move it around to get it into place , this could leave small air pockets or push the Artic Silver away from certian points . A contact pad would prove a more "fool-proof" way to ensure good even contact . Plz give us some more info on these samples ! i wanna try it too

 

[Hoot]

The day a TIM pad other than monolithic diamond beats a good application of AS3 is the day I hang up my OC efforts. Here is a link to a discussion about a water block that also addresses the need for a good mounting job and adequate spring pressure and balance.

Hoot

 

[WA2]

As i said on the other forums you posted this at.......

Yeah..i bet
I think you you need to learn how to apply AS3

 

[Mark Larson]

You can get the TIM at http://shop.store.yahoo.com/tai-sol/chompadt7qty.html

 

[SiliconX]

From what i've read, AS3 isn't really there so much to transfer heat from the cpu die to the block(don't get me wrong, it is a thermal compound and does transfer heat, that's why it's used), but rather, more there to fill in tiny imperfections in the die and/or block, as well as fill in any possible minute gaps created by not having the block mounted 100% perfectly flat. Thus, AS3 should be spread just enough to be a bit larger than the surface area of the die, and spread VERY thin with a flat surface like a credit card or something. The closer the die is to the block, the better.

If that is indeed true(and I would appreciate if someone could tell me if i'm on the right track, or incorrect), then I would imagine a thermal "pad" would tend to hurt your temps rather than improve them.

Maybe the pad lifted the block a little farther away from the cpu and maybe some airflow from a fan is now affecting the temperature diode, giving you an inaccurate reading?

Or maybe i'm just so incorrect it's not even funny

 

[BillA]

some observations on grease and pads (both TIMs of course)

understand that on a slow day I may make only 3 wb mountings, more typical is 4 - 5
and that I am really obsessive about the grease thickness (can you say 15min of re-respreading to 'get it right' ?)
and that I control the calibrated spring compression to ±0.0005"
(as one wb mfgr remarked, "Intel kind of stuff")

so how 'close' can I get ?
a good series of 10 mountings will be ±0.2° (with a measurement uncertainty of ±0.02°C)

what might 'typical' users experience ?
other than Hoot and those with a number of years of experience and considerable testing,
my guess would be ±1 to 2°C, IF they have very good procedures (which many do not)

my take on the first poster (Mark Larson) ?
too thick a layer (but could be non-flat as well)
but note that 'too thin' is also easy to achieve
there are MANY mounting variables, and finding that 'best' combination is extremely difficult
(and close to impossible for anyone outside of a lab to actually be able to demonstrate due to the myriad of 'small' influences)

"fill in any possible minute gaps created by not having the block mounted 100% perfectly flat"
wrong
learn how to mount the wb, the grease is to displace the air from surface irregularities

be cool

 

[black jesus]

You can get the TIM at http://shop.store.yahoo.com/tai-sol/chompadt7qty.html

$60? Why would anyone need 20 pads?

 

[Mark Larson]

a good series of 10 mountings will be ±0.2° (with a measurement uncertainty of ±0.02°C)

my take on the first poster (Mark Larson) ?
too thick a layer (but could be non-flat as well)
but note that 'too thin' is also easy to achieve
there are MANY mounting variables, and finding that 'best' combination is extremely difficult
(and close to impossible for anyone outside of a lab to actually be able to demonstrate due to the myriad of 'small' influences)

That is true. I'm the first to admit that i may not be a grease guru (most likely am not) but this is what it did for me. My results may be replicable, but there are too many variables.

As i mentioned:

Atleast that's what my amateur setup tells me in my personal system.

 

[BillA]

was not intended as a (harsh) critique
I have long advocated PCM pads in place of thermal grease

I do very much believe that the 'average' WCer/OCer would be hard pressed to beat a premium PCM with grease
(1,000 uninformed opinions notwithstanding)

thermal grease is good for testing because it is convenient, period

be cool