How effective are Thermal Compounds?

[Radiate]

Hey guys. I got a phone call from a friend. He has an Athlon XP 1700+

He said, when he bought the CPU the temperature was stable at around 30C, and now some months later it has risen to 70C
He said he had cleaned the heatsink and he doesn't know what Thermal compound is.

My preliminary conclusion was that the thermal compound had dried up, but I'm not sure...myself.

So i was wondering, can these compounds reduce the temperature by 40 degrees, or to put it another way: Can improper contact between sink and core raise the temperature by 40 degrees?

 

[BrunoPuntzJones]

<< Can improper contact between sink and core raise the temperature by 40 degrees? >>

Yeah. Tom's Hardware has a video where they take the heatsink off a running Athlon, little ah heck started smoking (probably the PCB of the mobo burning actually). If it's not mated right you could definately fry it. You have to have some sort of interface material.

 

[jiffylube1024]

<< So i was wondering, can these compounds reduce the temperature by 40 degrees, or to put it another way: Can improper contact between sink and core raise the temperature by 40 degrees? >>



Yes, especially with an Athlon XP, if you use NO thermal compound, you're just asking for trouble. Thermal compound is necessary for proper heat transfer and without any you will surely have very high CPU temperatures (which could damage the CPU). Get some Arctic Silver 3 pronto for your friend and apply it correctly (see their website arctic silver).

 

[WarCon]

On a new Athlon thermal compounds are not only recommended, I feel they are essential to keep your processor running more than a short while. If you friend was using the retail heatsink, then he had a thermal pad on it. Before you can use paste or a new pad, you need to clean off the old pad thoroughly. If your friend removed the heatsink for any reason, and tried to reuse the pad that came on it that would explain those high numbers. I have also seen some heatsinks that are so clogged with hair and dust that the temps rose nearly that much.

I recommend AS3, because it doesn't dry under the heat of an AMD, but there are other decent compounds out there. Just make sure they can handle over

Why does thermal compound matter, you ask? (Figured if you knew why, then my advice might mean something.)

Even though the core and the bottom of the heatsink looks very flat at the microscopic level it looks like a plain that is full of mountain peaks. In an ideal world the cores mountain peaks would line up with the heatsinks and there would be no air gaps. But since this world is far from ideal, what actually happens is mountain peak usually sits on mountain peak leaving all those valleys filled with air (air isn't a very good conductor of heat). Thermal compound is designed to fill those valleys with a material that conducts heat better than air. If the valleys are filled then heat can conduct into the heatsink, so that quantities of air can move it away (into your case if you have poor circulation). If you look at the actual surface area of both the mountain tops and of the valleys, you will see that the valleys make up a much larger percentage of that area and this makes the thermal compound essential. Also, you can see that you don't want much thermal compound (just enough to fill the valleys on both sides), or heat has an even further distance to travel, which lowers its performance.

Sorry for the verbosity.......

 

[Richardito]

Bad contact between the HS and the CPU can reduce your overclock substancially or even destroy the CPU. Remember that air is one of the best thermal insulators out there. If the HS is placed incorrectly and there is no complete contact between the CPU the HS there will be an immense heat build-up on the CPU. The thermal compounds acts as a spacer and displaces any air between the CPU and the HS, increasing the rate of thermal transfer between the two.

 

[Actaeon]

<< On a new Athlon thermal compounds are not only recommended, I feel they are essential to keep your processor running more than a short while. If you friend was using the retail heatsink, then he had a thermal pad on it. Before you can use paste or a new pad, you need to clean off the old pad thoroughly. If your friend removed the heatsink for any reason, and tried to reuse the pad that came on it that would explain those high numbers. I have also seen some heatsinks that are so clogged with hair and dust that the temps rose nearly that much.

I recommend AS3, because it doesn't dry under the heat of an AMD, but there are other decent compounds out there. Just make sure they can handle over

Why does thermal compound matter, you ask? (Figured if you knew why, then my advice might mean something.)

Even though the core and the bottom of the heatsink looks very flat at the microscopic level it looks like a plain that is full of mountain peaks. In an ideal world the cores mountain peaks would line up with the heatsinks and there would be no air gaps. But since this world is far from ideal, what actually happens is mountain peak usually sits on mountain peak leaving all those valleys filled with air (air isn't a very good conductor of heat). Thermal compound is designed to fill those valleys with a material that conducts heat better than air. If the valleys are filled then heat can conduct into the heatsink, so that quantities of air can move it away (into your case if you have poor circulation). If you look at the actual surface area of both the mountain tops and of the valleys, you will see that the valleys make up a much larger percentage of that area and this makes the thermal compound essential. Also, you can see that you don't want much thermal compound (just enough to fill the valleys on both sides), or heat has an even further distance to travel, which lowers its performance.

Sorry for the verbosity....... >>





Aaaaah, I read that article, It was from some australian site, and has some toothpaste and vegemite correct?

I have no intentions of flaming, but I suggest you link him to the article, or at least, quote the author who wrote the article. Rather than making it appear you wrote it. Like i said, no intentions of flaming, it would be just right to do so.


BTW: Thermal Compound helps alot. ^_^

 

[WarCon]

Actually its off of the Arctic Silvers site and was pre-Vegemite article I believe. I wasn't trying to plagiarize anyone's idea's, just relaying info. I guess it is only safe to give links..........

................edit................
That is also not a cut and paste, but relayed in my own words from memory as it was relayed to me from some other nice ATer when I was first looking into thermal compounds and why they are so important.

Thermal Interface Basics is a link to the article. I only browsed the Vegemite article, so it wouldn't have came from there mate........

But I did find it fasinating that Vegemite is such a good thermal compound. I actually read enough to find out what the heck Vegemite was though.

 

[Actaeon]

I see, sorry to bring something off topic up.

I just don't like plagerism But thank you for understanding that I wasn't trying to make a big fuss out of it.

I see that example of the Mountains and Valleys must be widely used term. I must be wrong about the webpage where I found that phrase from, because it isn't on the "Vegemite" Page. I do remember reading it elsewhere. Once again, I apologize for it up.

Vegemite webpage. Its an interesting article. On uh.. Vegemite, and Thermal Compounds. Radiate, I suggest you check it out.