Reapply Arctic Silver every year - good idea?

[GrefMofovich]

Hi, this idea just hit me out of the blue, but maybe it's a good practice to renew your AS3 layer about once yearly for increasing cpu life? kinda like regular maintenance for a nice car! (yes sadly my Athlon XP is my ferrari :D)

so anyway, I took out my board and unfastened the heatsink yesterday to see what was going on. wish I'd snapped a pic, but what I saw was basically a large brownish-hued splat where I had applied the AS3 about 11 months ago... yes the AS changed color. guess all those nights of leaving comp on took their toll on the stuff. the cpu was still very shiny (after I wiped it clean) and looked quite healthy. (I don't typically check my temp but last time I did it was in the high 30's C I believe. that's at idle...) the funny thing was that there was a reverse "amd" lightly imprinted on the heatsink contact point. not sure whether that means the letters part of the die is cooler or slightly hotter, but I got a kick out of it anyway. will report results of re-applying the AS... any thoughts?

-GM

ps Here is another AS3 related thread I found:
http://www.sysopt.com/forum/showthread.php?threadid=116835

[Magua]

From Arctic Silver website

Due to the unique shape and sizes of the particles in Arctic Silver 5's conductive matrix, it will take a up to 200 hours and several thermal cycles to achieve maximum particle to particle thermal conduction and for the heatsink to CPU interface to reach maximum conductivity. (This period will be longer in a system without a fan on the heatsink or with a low speed fan on the heatsink.) On systems measuring actual internal core temperatures via the CPU's internal diode, the measured temperature will often drop 2C to 5C over this "break-in" period. This break-in will occur during the normal use of the computer as long as the computer is turned off from time to time and the interface is allowed to cool to room temperature. Once the break-in is complete, the computer can be left on if desired.

[chubtub]

I though that once it was put on that you should leave it as long as it is working. The longer the better from what I have heard.

[GrefMofovich]

Ok, I didn't know about the break-in period, that's useful info :) But what about breaking down? I guess it would take a chemical engineer to answer that one... It's not completely crazy to think that it would just go on working perfectly year after year or even slightly better over time, but on the other hand I'd like to take better care of my cpu's if I can.

Here's some data after applying a brand new layer of AS3:

after 30 minutes off-time:
cpu temp = 26 C / 78 F
system (mb?) = 22 C / 71 F

computer on for several hours but mostly idle:
cpu temp = 43 C / 109 F
system = 31 C / 87 F

high cpu load (for over 2 hours):
cpu temp = 50 C / 122 F
system = 34 C / 93 F

I use the stock amd fan that came with my XP 1700 (Palomino) and it's about 72 +/- 5 degrees F in the room.

-GM

[mobiker]

I don't know I have never kept a computer for a year. I seem to build a new one about every 6 months. That way I still get a good price out of my old stuff.

[Someone Stupid]

Seems even with the usual few C drop after beaking in, it really didn't need reapplication. I know some who swear by reapplication, but I've never been one of them as I've never seen any heat changes. Mght have risen a couple C over a year without me noticing on the rig I had AS2 on, but that is it - anymore and I probably would have noticed.

[causticVapor]

All thermal greases pump out, including AS3, and should be reapplied every now and then. What happens is the grease spreads out, becomes highly diffuse, and finally does not bridge the gap between core and HS.

Grease is grease; it moves over time. While AS3 is more resistant to pump-out than most cheap greases, it still suffers from it to a lesser extent.

[Magua]

AS5 is quite a bit thicker than AS3. If you notice your temps are really high, reapplying is a good idea, otherwise periodic reapplications are not worth the effort. If the thermal compound does break down over time, I would imagine it would take years.

[causticVapor]

The thing is, it does not break down, but instead spreads out from mechanical expansion and contraction, ever so gradually. Periodic application every six months or so is required for good performance.

Grease is grease. It is not solid-state.

[Magua]

So you are saying that the grease will slowly flow out from between the HSF and CPU? If thats the case then wouldn't you see paste oozing out from under the HSF? In my opinion if the temps arent rising, then the paste is doing its job. I don't see a reason to reapply every 6 months if you aren't having temperature problems.

[Bat25]

If you don't pverclock - no need to re-apply so often, if you OC, then I would re-apply every 6 months to 8 months.

[Magua]

I don't get why you would want to have a blanket policy of reapplying thermal paste (reguardless if you OC or not). If your temps stay steady, its working fine.

[RamonGTP]

Originally posted by Magua
So you are saying that the grease will slowly flow out from between the HSF and CPU? If thats the case then wouldn't you see paste oozing out from under the HSF? In my opinion if the temps arent rising, then the paste is doing its job. I don't see a reason to reapply every 6 months if you aren't having temperature problems.

Unless you use the whole freakin' tube, the "oozing" shouldn't get far enough for it to be visable from behind the heatsink. A little use of common sence and you could have figured that out on your own.

[gjimene2]

alot of the times you may only need a razor thin application of AS3 or AS5

[Magua]

I understand that and use barely enough to get it to spread over the chip, I was only responding to causticVapor's post about the paste spreading out enough that it wasent effective. If nothing escapes from the sides (which it obviously dosent) its still there, and there is no need to reapply. If temps aren't rising, a new application of paste won't help, and if anything will raise temperatures until it finishes its 'break in' period again.

[RamonGTP]

The core is a lot smaller than the HSF surface. The compound can infact spread away from the core and collect AROUND it... Once it escapes from between the core and the HSF it will not ooze anymore because it is no longer under any pressure squeezing it out.

[Magua]

Ahh ok, I see what your saying now. However, I still won't replace my paste unless I see a problem with my temps.

[Someone Stupid]

You still have to remember that while gravity may be pulling it downward, after it has set, probably a bit after, not much more movement is taking place. While it is a grease, it still does some adherance, and with a heatsink that exherts a lot of force, the grease that is left really isn't going anywhere as the die is flat as is a good highly and properly lapped heatsink, so there is no angle to help push the grease out of but a good bit of pressure to hold it in place. It makes flat contact. A weaker heatsink clip or lower quality surfaced one you probably might get some loss, but I still don't see it being enough to overcome the compound's own viscosity especially when sandwiched at high pressures.

It's pretty much a do it if you feel like you need to or notice you need to due to rising temps and that is the only possible culprit as everything else has been checked over - fan spinning, heatsink clean of dust, same airflow and ambient temps, then I'd reapply, other than that, if the temps are stable, I prefer to leave it well enough alone - though it is hell getting my heatsink on and off. I'm not to say to do it or not, just I don't. :)

[GrefMofovich]

Well my computer has oficially started suddenly rebooting under high loads. Seeing as this happened after I reapplied AS-3 compound, conclusion: I should have left it alone.

Although last time when I caught it rebooting I entered bios right away to get the temp readout and it was 50 C (122 F) or 7 degrees above idle temp. This was at max load, and didn't sound like so unreasonable an increase to me. I'm going to just replace the stock hsf with a Volcano and hope that solves the problem...

[tgxiii]

How much did you apply? You're supposed to put only a thin layer. If the AS3 is too thick, it actually insulates the heat, making things worse.

[Direct1]

One of my desktop machines that I built in July of 2002 with an AMD 1800+ & stock HSF with AS3... Idle temps were around 44C and now are around 40C almost 1.5 years later. I don't think there is a need to re-apply AS3. Just my $.02 worth. Good luck! :t

[causticVapor]

Something that has to be remembered is that the phenomenon is not called leak-out. It's called PUMP-out, and with reason - no matter how tightly an HSF is pressed against a CPU die, the grease will pump out from the thermal compression and expansion. The only way to lessen the effect is to lower the temperature that the interface material is subject to.

Greases can pump out so dramatically that the die is clean and devoid of any grease within two years or so. With AS3, the effect is much less drastic, but not eliminated. Several have noticed pump-out with AS3; after all, it wears away just like everything else.

This is a well documented phenomenon. Why not just be prudent and replace the grease every six months? It's not like you're going to lose anything - that stuff has low shelf life anyways.

[zybch]

Nobody seems to have the correct idea about what thermal grease is for.
It is NOT for providing a thermal transfer layer between the CPU and HSF. Heatsink paste generally does a poor job at transfering heat from one hot surface to a cool one.
What it does do well and what it is designed for is to fill in the microscopic air pockets and scratches that literally cover the surface of the die/HSF.
It isn't a great heat transfer material, but is many many times better than the air it replaces and most other non-evaporating liquids.

Install a HSF on a CPU with the reccomended ammount of thermal grease and then remove the HSF and you'll see that there is barely enough grease left on the die itself to be visible. The majority of the grease has been squeezed out from around the edges.
What is left is enough to fill in the air pockets, not to provide a layer of heat transfer material.
As the processor heats up and cools down, the small air gaps are gradually filled with compound (thus the burn-in period), re-application after 6/12 months has to start this process again.
The air gaps as so small that there is no 'leaking' of the compound, surface tension is more than enough to keep it all where its supposed to be.

Thankfully AMD has finally stopped sticking a thermal pad (parrifin wax as the gap-filler) to the bottom of their stock coolers.

[SLX]

Remember what zybch said, Its not how much you put on as long as you get a even thin layer on. So that you have alot of cpu - heatsink contact. The paste just fills in the valleys. If your having stuff 'ozze'e out then your wasting good AS3.

Thus

If you never move your computer then you dont have to reapply it for a very long time. I mean its grease, its not going to degrade for at least a year or 2.

However

I think its needed to reapply if you are a person that moves the computer around alot. I have a Alpha pal 8096 that has 4 tight screws on it. However thats not going to prevent the HS from microscoppppicly shifting off of the CPU, when im blazing down I15 at 85mph ;)

[Jimmy D]

Arctic Silver has found it's match. Check out this grease being sold on eBay, SPECTRA COOL.

http://cgi6.ebay.com/ws/eBayISAPI.dll?ViewSellersOtherItems&userid=greatpcstuff&include=0&since=-1&sort=3&rows=50

Users are reporting outstanding results with up to 20 degrees C reduction in cpu temps and there is no break in period to fool around with.

:t

[zybch]

I've just started using AS5 and it has a small improvement over AS3 which is what I used previously.
Quite frankly I wouldnt trust that stuff on eBay until I see it independantly tested.

[SLX]

Originally posted by Jimmy D

Users are reporting outstanding results with up to 20 degrees C reduction in cpu temps and there is no break in period to fool around with.

:t

*sarcastic... So if I use this stuff with my alpha pal p4 heatsink that currently runs at 30 deg C it, I will get temperatures of 10 Deg C?

[tgxiii]

C'mon, now... I highly doubt that any grease would cause drops in temperatures by that much. Maybe you meant 2 degrees....

[Mr. Thompson]

LOL, how about more of the eBay goop for less.

Here's a couple of links for enquiring minds. ;)

http://www.altex.com/product_info.php?products_id=1170

http://www.altex.com/product_info.php?products_id=1169