Thermal Compound Users Beware !! More Fraud

MrAl · Dec 8, 2004

Hi there,

I was looking up some thermal compounds for aiding
in the thermal conduction from semiconductors to
heat sinks and i ran across this article explaining
that some of the thermal compounds who's packaging
indicates a high silver content in fact has NONE !!

Please read through to the end as at least one
manufacturer voluntarily recalled the product.

http://www.overclockers.com/articles938/

The only thing they didnt do (strangely) was test the
thermal conductivity or resistance. It would be
good to know if a 'bad' material was used on say a
CPU heatsink would it cause unusually high temperature
rise, which is the more important point.

Take care,
Al

hank · Dec 8, 2004

Good link.

There are standard thermal conductivity tables for the metals; silver conducts heat better; cheaper products use copper and zinc as did the mislabeled ones - it sounds like simple fraud.

KevinL · Dec 8, 2004

Yup....that article's been around for a while.

Personally I don't buy into the "silver" hype. When I last passed thru Arizona more than half a decade ago, a colleague and I popped by this electronics warehouse to buy a can of Thermalloy Thermalcote 'white' grease. The can looked at least 5 years old back then, so it's probably 10 today. I got two POUND cans of the stuff, $5 each.

Of the hundreds of computer systems passing through my hands that have been treated and coated with those things, none of them has ever failed because the grease failed. 5+ years is around the service life for computers anyway.

The same grease takes care of protecting my Luxeons. I have one setup running a WX1U and pushing nearly 7 watts (high Vf plus 20% overdrive) through the emitter and the heatsink heats up really fast - the grease must be getting the heat through to it.

Same tips apply, use a razor or box cutter to apply a paper-thin (or even thinner, depending whether you can do it) film of grease to the surfaces. A little goes a LONG way. Do it like you're buttering bread - VERY gently. Gone are the days when I'd squeeze the whole darn tube onto the CPU and smack the sink on..... thankfully! I was young and stupid once. Now, I'm old and still stupid. Oh well. /ubbthreads/images/graemlins/icon3.gif

Technique matters.

MrAl · Dec 8, 2004

Hi there,

Yeah /ubbthreads/images/graemlins/smile.gif
I use the white silicone based stuff too, and it works
fine. I think any of these work very much the same, and
i've seen lots of web sites where people tested theirs
and the maximum difference was about 4 degrees C i think
between 'good' stuff and 'not so good' stuff.
I've read the zinc based stuff is the worst, but never had
the chance to test it.

I've also seen web sites that tested the 'top of the line'
heat sink pastes and they all indicate there are only fractional
differences in temperatures when used on the same device
under the same conditions.

Strange, but i've also read that the warrenty on AMD
cpu's (maybe not all of them) will be voided if using
Artic Silver or ANY other grease. AMD explained that
for some reason the slightly conductive greases could
cause a problem, so they recommened only one kind of
grease and state that anything else voids the warrenty.

I've also read that thermal 'pumping' could cause
some of the material to pump out from the
gap between device and heat sink, but dont seem to
find much about this on the greases themselves.
Also, after seeing the cheap white stuff work for
so many years on so many products it's hard to
believe there could be a problem.

Take care,
Al

smokinbasser · Dec 8, 2004

The white silicone thermal paste is all that most solid state traction control systems reccommend even with the teflon slip sheets used.

koala · Dec 9, 2004

I use white silicone compound on all cpu and heatsinks, haven't come across any problem. However, I have seen an Intel Celeron, I think it was 433mhz. The cpu has pins exposed on the top, smeared with the silicone compound. It refuse to boot. I scrub it with soap and detergent, it worked. Until today, I dont't believe it was the cause of the problem.

The white silicone compound is pretty good for cleaning too. When wiping it off, it removes abit of the aluminium and leaving the surface shiny.

When I leave a large tube sitting too long, some yellow oily liquid will part with the compound makes it messy. Have you guys seen that? I wonder what it is.

I think those paste that contains silver are for the extremist overclockers who want's to squeeze every drop of juice from their cpu. I will not spend extra $$ in these except for the epoxy type.

So believe in the Product but not Marketting /ubbthreads/images/graemlins/grin.gif.