Galium Thermal Compound update (read... this time its weird)

[Flat]

ok using copper shim/HSF attached to the CPU with some lock-tight a friend gave me, and with the shim & HSF together with arctic silver epoxy... and galium layer over core (Hedgehog HS), I am idling @ about 30-32, full load 36-37. this is down from about 34-35 idle with Arctic Silver, 40-42 max arctic silver. I expected results similar to this before reading several post about thermal conductivity which stated that the thermal conductivity was as follows:
Thermal conductivity for galium = 0.406 Wcm-1K-1
Thermal conductivity for silver = 4.29 Wcm-1K-1

This would seem to imply that regardless of melting point arctic silver should be out performing my galium "pad"? If thats the case what could be going on here? Is it possible that the copper shim fixed with silver epoxy and that firmly attached to the CPU is causing the lower temps? Ideas?

 

[conlan]

Flat... i doubt its the shim , i think your on to something here

 

[Spoooon]

I think it's the fact that when the gallium melts, it expands. That would create a better bond between the core and the heatsink, allowing for better transfer. What you basically have is liquid filling all the gaps between the core and the heatsink. One thing: what cpu are you using?

 

[Flat]

Athlon 1.2gig, not oced yet. interesting theory, liquid would make better contact therefor leading to higher heat transfer. it is possible that the silßer cant use all of its transfer potential due to a lack of surface area...

 

[Spoooon]

If you've read some of the threads going on in this forum, you probably noticed the posts concerning the inaccuracies of Socket A temps. Mikewarrior's homepage has info on it.

 

[Bignate603]

true, but you can still use the readings of the thermsistor to compare, even if it's inaccurate. All he's changing is the stuff between his chip and the HSF. Very cool...

 

[Flat]

Spooon your opinion on the surface area comment?

 

[Jwyatt]

Nice work Flat. One question. How in the hell are you going to get the HSF off the cpu with that mess you got now? It seems to me you are on to something here.

Im working on a peltier/water rig right now. Taking a while to get my 150watt pelt here though. I might consider using something like your doing to attach the cold plate to the pelt then the pelt to the water block. I will use artic silver for the cold plate to the CPU.

Where can I get some of that Galium?

 

[Flat]

hmm where can you get galium... I get it from my dad (colledge admin picks it up from chem department) I dont know where you could get it

 

[Spoooon]

What you said about the arctic silver is probable. You could test it by creating some manner of peltier test bed like 2cooltek does. Try different surface areas etc and see what happens. Obviously, the greater the surface area, the better the performance. But atleast you would have the numbers to back it up. Probably be safer to test your gallium stuff too, rather than risk the life of your computer.

edit: To get the stuff off you can just put on a rubber glove and let it melt off the cpu and heatsink onto your hand.

 

[Mikewarrior2]

Are you comparing gallium to pure-silver, or arctic silver?


Mike

 

[Halz]

Here is something to look into... fusion enthalpy. In comparison, this is really the only significant value I have found between the other common heat exchange mediums (in a 'paste' form); copper, aluminum and silver. Gallium is nearly half that of silver, for example. Half again for copper and half once more for aluminum. My only question at this point is why an element such as lead (which has a value comparable to that of gallium) where not used in the past. Perhaps some other 'adverse' properties of lead come into play; crippling its capability.

 

[Spoooon]

Maybe you can get your hands on this stuff: Black Ice.

material/thermal conductivity (W/m-K)
Black Ice/900
Copper/400
Aluminum/200

It's meant to be used as a substrate material. Perhaps they could construct a heatsink out of it?

 

[Flat]

WOW that Black Ice is the sh*t!

 

[Dexion]

<< My only question at this point is why an element such as lead >>


Lead is definately not used in public, infact, no lead is used in an household item. Lead can is a lethally toxic water contaminant and very environmentally unfriendly. Infact, history has shown that numerous unaccounted people have died from this silent killer which was once used in build aqueducts, can food, and build water pipes.

 

[Spoooon]

Lead is responsible for &quot;mad hatters&quot;. Also, the possible cause of Rome's downfall.

 

[pbrain]

ot, but i actually think it's the use of mercury in the hat making process that causes mad hatters. the body slowly absorbs the stuff and it goes straight to the brain.

 

[Spoooon]

Argh, that's right. Got my elements mixed up.