Thermal paste questions

I recently upgraded my system, and I received the standard thermal paste that comes with CPUs. I wasn't happy with this regular stuff so I wanted to upgrade. I couldn't find anyone near me that carried Artic Silver so I did some research on what else there was. I found this page that gives a detailed comparison between ten of the top ones and I decided on getting Cooler Master Premium Thermal Compound with Shin Etsu because a shop I go to carries it and the price is worth the trial (IMO). And according to the comparison, Cooler Master was the better of the two.... But honestly I trust the tons of people on here that swear by Artic Silver. I just got the Cooler Master because of accessibility. Even if it isn't the better of the two, it has got to be better than the standard stuff they ship with CPUs.

Anyway.... long story short, I tried it and my temps aren't any different. System at idle with nothing running it hovers around 50 and 51º C. Under a load (SETI@Home running only) my CPU is a stable 57º C. I realize these temps aren't anything to worry about, but I'd really like them to be much lower. As far as case fans go I'm fine there.

So my questions are:
Would I notice a dramatic difference if I got Artic Silver?
Anyone had any experience with the paste I ended up using?


The stuff is thick too. Not the easiest to apply. Like spreading peanut butter on flimsy read :( and as a result I might have gotten it too thick.

SYSTEM:
CPU: AMD Athlon 2200
MOBO: Gigabyte GA-7VT600-L
Video: ATI Raedon 9000
RAM: 512MB PC2700 Crucial RAM
OS: Windows 98FE
Case Fan: Cooler Master SAF-B82 (rear, exhaust)
CPU Fan: Dr. Thermal, not sure of model #

There are many quality pastes. Yes, I use AS... but generally speaking there is not a huge amount of difference between this and that.
The thickness you mentioned could be a problem... you might try reseating. Warm the tube with a blow dryer, give it a little more spreadability.
Now... what will make a major difference is your HSF.... What are your specs in that department. Saw the Dr. Thermal fan... that a heatsink too?

I've tried CoolerMaster's compound before, but I also don't like the way it spreads. I've never tried AS, so I couldn't compare them, but even the cheap stuff that comes in those white packets seems to have a better consistancy. Then again, I guess being thicker makes it last longer.

Anyway, thermal compound is kind of a pointless thing to debate. I would have gotten Arctic Silver if it had been in stock when I ordered my parts, but I was just as happy getting something else for the same price. Really, at best, you'll see a 2-3 degree difference. That's nominal.

What really makes the difference are your heatsink and your case's cooling. If you can, try to fit a rear case fan so that it will blow directly onto the CPU's heatsink... it will work with the heatsink's fan to cool the fins. All your case fans should be blowing inward, except for your power supply fan. This pushes a maximum amount of cold air into the case, allowing the warmer air to escape out the top. It's best to have fans blow directly on components, such as your hard drives, CPU, and video card.

You really need to have at least two intake fans on the case (one front and one back), along with the power supply's exhaust. I have four intake fans - one for the hard drive, one for the video card, and one for the CPU, plus an extra fan in the bottom to push more air. My case temp and CPU temp are both very low (CPU never gets hotter than 40 degress, even under extreme stress... it's an Athlon 2600+).

I'm pleased you have good results with that fan arrangement Dr. Gibbs. But, if your PS is the only exhaust fan... I'd be uncomfortable with that. The PS fan is generally low rpm and is meant primarily to cool the PS... and you want it to vent all the hot air through the PS... hummmm.
An intake fan disturbing the air around the CPU fan may simply reduce it's effectiveness. Aerodynamically... And with that much intake I'd think a bit of dust may be an issue.
General rule of thumb is front and side are intakes, rear and top are exhaust. But depending upon your case and cooling preferences, feel free to experiment.

Here is the link to Tiger Direct's page for my CPU fan and heatsink. It is rated to handle up to a 2800+ so it would make sense that it would be plenty for my 2200. But then again maybe it isn't.

If I get the thermal paste too hot before I apply it, won't I run the risk of causing it to cure prematurely? Besides: single, bald men don't typically have hair dryers :D

I'll answer more of the questions later today or tomorrow. Ho, ho, humbug.

Thanks for the replies

Here's one of my favorite HSF's...

Using this one now.... Although mine is the 800U model...

The Thermalright is a bit beefier but the Vantec is quite good also...
Grease doesn't harden when it cures and we're not talking blow torch heat... put the tube in some hot/warm water. Just make sure you don't get any moisture in it during application......

I've tried a lot of different methods, and I've never had any work better than what I'm doing now. 40 degrees is pretty darn good for a 2600+ :)

Quote:

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Originally posted by Dr.Gibbs
I've tried a lot of different methods, and I've never had any work better than what I'm doing now. 40 degrees is pretty darn good for a 2600+ :)

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Just goes back to experimenting with your particular setup... whatever works.

Dr. Gibbs:
How big of a power supply do you have on your machine? I'd imagine you have a good sized one since you have so many fans. I'd be afraid of maxing out mine if I had that many fans.
Anyway, my new PS has two fans, one intake and one exhaust. That plus my Cooler Master case fan on the back of the case sucking out is all I have. I tried putting the case fan in the bottom front sucking in cool air, but because all I had sucking out was the PS fan my temps went up. I had to cut a hole in the plastic on the front of my case to get better airflow, and I think that helped a little. I'm also getting ready to cut the case in the back where my fan goes so there will be less resistance and hopefully it'll work a little better. The holes they cut in these cases for the airflow isn't worth a poop :mad:

What kind of HSF are you using, and what kind of fan do you have for your video card? I think that the next fan I get will be for the video card, but I'm not sure what to get.


Abhoth:
That second heatsink is very different than any I've seen. But I looked at the link you gave and the link that newegg.com gave for the vendor and neither link had a picture of the fan, only the heatsink. I'd like to see that fan since it pushes 110 CFM :)

I'll try to heat up the thermal paste and get a thinner layer sometime soon. How thick is too thick though? What I just put on is a little thinner than a credit card. I've heard it is supposed to be thinner than a piece of paper? Is that right? Don't quote me as I may be wrong, but I think I read that somewhere.

The Thermalright HS is just that, a heatsink. You can put a variety of fans on it... does not come with a fan. On Thermalright's site they mention the Tornado I believe... that's the CFM monster. Very loud fan so if you don't have some sort of fan controller I'd shy away from that one.... I'm running the Thermalright HS and the fan I'm using is the TMD fan off the other HSF link I gave you..... If you're not overclocking I wouldn't worry too much about the Thermalright..... the HSF in the first link, the Aeroflow, is excellent for general use and some mild overclocking.

As far as thickness goes... they say you should almost be able to see through the layer.... I do it a bit differently.
I have the little laytex finger covers, like a surgical glove, only for your finger.
I squeeze a tiny bit of AS on the die, then daub it lightly with the gloved fingertip... once the die is covered I put a new one on and smooth it out. Very neat and tidy!

Quote:

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Originally posted by Parallax
What kind of HSF are you using, and what kind of fan do you have for your video card? I think that the next fan I get will be for the video card, but I'm not sure what to get.

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It's just the retail HSF that came with the 2600+ CPU. It's actually very good. It's really quiet. I've been told the AMD heatsinks were awful, but I was pleasantly surprised (I decided to give it a shot, and I'm glad I did). I was using a Thermaltake Volcano 6 on my old 1600+ CPU, and it wasn't anywhere near as nice as AMD's.

My video card (GF2 MX400... yes, I know I need to upgrade :p) doesn't have a fan on it, but there's a fan in the side of the case next to the AGP port that blows over the card's heatsink. I think that's probably more effective, since it takes cold air from outside the case, instead of just moving warm air around the GPU. I think the same is true with the CPU -- it seems that having cold air being blown through the fins would do much more than blowing warmer air down into them. I bet if I reversed that fan, I'd have higher temps.

Power supply is just a 350 watt. Doesn't take much for fans.



To me, it makes the most sense to have as much cold air being blown into the case as possible. It doesn't seem like blowing air out of the case would be that important, unless you're blowing it out of the top, where the heat tends to get trapped. I used to have two exhaust fans and one intake, but that never worked as well. All I know is that this is the first time I've reached into my case and it hasn't felt any different from the room temperature, and my temps are better than they ever have been before. What else could I recommend? :)

Here's a page of VGA HSF's...

Be sure to check compatability...

Quote:

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Originally posted by Dr.Gibbs
I've tried CoolerMaster's compound before, but I also don't like the way it spreads. I've never tried AS, so I couldn't compare them, but even the cheap stuff that comes in those white packets seems to have a better consistancy. Then again, I guess being thicker makes it last longer.

Anyway, thermal compound is kind of a pointless thing to debate. I would have gotten Arctic Silver if it had been in stock when I ordered my parts, but I was just as happy getting something else for the same price. Really, at best, you'll see a 2-3 degree difference. That's nominal.

What really makes the difference are your heatsink and your case's cooling. If you can, try to fit a rear case fan so that it will blow directly onto the CPU's heatsink... it will work with the heatsink's fan to cool the fins. All your case fans should be blowing inward, except for your power supply fan. This pushes a maximum amount of cold air into the case, allowing the warmer air to escape out the top. It's best to have fans blow directly on components, such as your hard drives, CPU, and video card.

You really need to have at least two intake fans on the case (one front and one back), along with the power supply's exhaust. I have four intake fans - one for the hard drive, one for the video card, and one for the CPU, plus an extra fan in the bottom to push more air. My case temp and CPU temp are both very low (CPU never gets hotter than 40 degress, even under extreme stress... it's an Athlon 2600+).

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Excuse me Dr. Gibbs, but I got a question, Usually the back of the PC is very dirty and dusty, and doesn't get cleaned very often, if you put a Intake fan in the back, would you be introducing more dust into the case? What I understand is the Front of the case(cleaner) is the only intake I'm suposed to have, correct me if I'm wrong.

Has your case stayed fairly clean?

and If I wanted a Filter on my Intake Fans, What kind of material am I looking for as the element?

I've seen some of that Blue "Washable" "cut to size" filter material, Would that be fine, or would It restirct Airflow too much?

Or am I worrying about dust too much, and dust inside case is ok?

Generally low in front for the intake and of coarse high in the rear for the exhaust is the best. But must admit that the case itself can make a difference in what you can get away with. My InWin S500 case runs a lot cooler than my server towers. And with a whole lot less fanage.

Those Green scrubies work just fine for filters, but they do tend to plug up so you have to clean them more often. Or you can get filter material like they use in furnaces and cut it to size.
Lots of options, but we have to experiment to find out what works best for us. Even if it be a stand alone room air filter unit that is portable.

The idea of the thermal paste is simply to fill in the microscopic imperfections in the mating faces of the heatsink and processor die, so it should be as thin as possible. No thicker than a sheet of paper for sure. These instructions are useful:

Arctic Silver Instructions

Quote:

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Originally posted by Murf
I agree with DrMDJ with a fan above the PS (I use this concept)athough ski's config is also a good one and inline with an Example from the AMD site;


http://members.cox.net/joemurphy/cooling.gif

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I just don't want somthing like THIS to happen....

http://keepernsol.com/RyanHomes/ryan...s/Ryan_p22.jpg

So This is how I'm going to do my case, the front lower fan will be Intake.(filtered)

the back Top Case fan will be INTAKE(filtered)

the back Bottom case fan Will be Exhaust, and the power supply(bottom intake)(middle) exhaust, sounds okay?

So basically My system looks like that picture, except I got a tall tower, so there is room above the power suppy, and it has a case fan just above the power supply.

or Do I need the bottom rear to be a Intake and the top rear as exhaust?:confused:

Quote:

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Originally posted by SuperSparks
The idea of the thermal paste is simply to fill in the microscopic imperfections in the mating faces of the heatsink and processor die, so it should be as thin as possible. No thicker than a sheet of paper for sure. These instructions are useful:

Arctic Silver Instructions

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But wouldn't the excess paste just Sqeeze out?

Nope, but it might crack the motherboard. It's happened before.

Quote:

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But wouldn't the excess paste just Sqeeze out?

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Yes,,but if it 'squeezes out' onto the CPU bridges,you can be in deep trouble...:(

And,, imo,,the most reliable airflow thru' a case is as descibed in the schematic given above: Intake low in front, exhaust high in rear. Intake in front and intake in rear=hot vortex in my experiences...:rolleyes:

As said above the purpose of the paste is to fill voids, imperfections between/in the mating surfaces of the cpu slug and the heatsink. The concept is that the paste is a better thermal conductor than air, so you want the paste to replace the air gaps that would otherwise exist in the voids/imperfections. However, paste inhibits thermal conduction (acts as in insulator) when it exists in places where the metal surfaces of the slug and heatsink could otherwise meet properly. So you don't waste (or want as little as possible) in these areas. The "ideal" would be to have paste only in gaps and none where good metal-metal contact can be made.

Paste will melt and flow under heat conditions (and part of its eventual effectiveness is dependent on this), but only to an extent. So if you have a lot of excess it will not all flow or be forced out (by the pressure between the heatsink and slug). Instead you end up with a buildup, contributing to the insulation effect described above.

Okay, since no one seems to believe me, I flipped my rear fan around to check the difference.

Blowing in: 41°C
Blowing out: 45°C

Maybe my case is a freak, but I'm sure not. I don't just make this stuff up, ya know :p

Tons of good advice here... thanks everyone :)

Ok, I understand how much thermal paste I need. I did in fact put too much on. I'll be taking it apart and trying it again shortly. And I'll be sure to warm up the paste before I try to work with it. Also, I'm asking for a gift-certificate to this computer shop I go to for Christmas. Hopefully Santa will put it in my stocking and I can get a fan for my video card.

And while I'm talking about video cards.... Fans for video cards work the same as the CPU fans, right? They blow air *onto* the chip, right?

Thanks for the link Abhoth. Almost all of those are well within my price range :)

As of yet, I don't have any air filters on my system. I've always prefered having as few restrictions as possible for the airflow and just clean out my system every so often. I have never had much of a problem with dust anyway. But now with these scrubbies being so popular I might invest in some.

Quote:

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Originally posted by Parallax
They blow air *onto* the chip, right?

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Yup. It would probably work either way, but that's the most effective. It pushes the most through the heatsink.

And I can tell you of a 4c temp jump on my wife's system when I switched the rear fan to intake. Changed it back.
It really depends upon the case... the case makes a huge difference. There is the 'rule of thumb' that I follow... but experimenting with your particular case and such is permitted... ;-)

Something to note... When dealing with temperature differences such as was mentioned above and within the range being dealt with the difference is not really meaningfull. The values are already well within a perfectly acceptable range of operation and as such no greater stability or meaningfull extension of the processor life is going to be had. The benefits of cooling are subject to diminishing returns. Often times these days money and effort is put in to reducing temperatures beyond a point where there's really anything to be gained short or long term.

I figure as long as you are below 60C, why worry about it. 67C and above, now I get busy real quick.

Yeah, you start pushing 60c or beyond and it's time to rethink something!
Was more a commentary on fan placement and efficiency than temperature. Temp differences are simply noted as a barometer of that efficiency.