CuSil Alloy, just a myth...

Trip · Post by **Trip** » Mon Feb 16, 2004 11:31 pm

Material _____Thermal Conductivity ( W/mK ) __% gain over Copper
Copper Alloy 110 _______388 _______________NA
Pure Silver ____________418 _______________7.7%
Cu-Silver Alloy _________515 _______________32.7%

silvervarg · Post by **silvervarg** » Tue Feb 17, 2004 2:19 am

Hm, very interesting if it is true. I will remain sceptic until the numbers are verified by more reliable sources.
Since the name "AquaStealth" is not very well known and loads of strange companies like to abuse the work "Stealth" I put little trust in the numbers.
If Copper-Silver alloys had these good values we would probably have heard about it's use in electonic circuitry long ago.

wheredoibegin · Post by **wheredoibegin** » Tue Feb 17, 2004 3:09 am

Sounds very promising (and expensive).
However considering the thermalright coolers cost AU $100 and the heatsink->air interface is the real trouble spot i dont think i'll be buying any silver/copper coolers any time soon.

Where was this from by the way?

Trip · Post by **Trip** » Tue Feb 17, 2004 7:01 am

CuSil

Maybe the same as Coin Silver: 82% silver, 18% copper.

jojo4u · Post by **jojo4u** » Tue Feb 17, 2004 7:08 am

http://www.overclockers.com/articles305/ wrote: Mr. Toshi Oyama, Ph.D. R&D Manager, WESGO Metals recently informed me "that the thermal conductivity of Cusil was calculated from Electrical conductivity, which is reasonable since both are controlled by free electrons in metals. However, electrical conductivity of Cusil was measured about 30 years ago with a very primitive machine. I re-measured it, and calculated Cusil thermal conductivity to be 371 W/m/K."

This means that the article's value of 515 W/mk (originally found on WESGO's website) is incorrect and the graph and calculated values for Cusil's heat spreading resistance should be disregarded

Trip · Post by **Trip** » Tue Feb 17, 2004 7:15 am

Wow, good eye!

Oh, you got that from another website. Scroll down to the bottom of the previous link - the exact same statement is at the bottom

- I guess CuSil is a myth.

sgtpokey · Post by **sgtpokey** » Tue Feb 17, 2004 7:16 am

actually the same disclaimer is in the link you have as well Tripp:

An Update on Cusil (or A Silver Bullet Turns to Lead)

1/21/02

Mr. Toshi Oyama, Ph.D. R&D Manager, WESGO Metals recently informed me “that the thermal conductivity of Cusil was calculated from Electrical conductivity, which is reasonable since both are controlled by free electrons in metals. However, electrical conductivity of Cusil was measured about 30 years ago with a very primitive machine. I re-measured it, and calculated the thermal conductivity to be 371 W/m/K.”

This means that the article’s value of 515 W/mk (originally found on WESGO’s website) is incorrect and the graph and calculated values for Cusil’s heat spreading resistance should be disregarded.

Trip · Post by **Trip** » Tue Feb 17, 2004 7:21 am

myth breaker

scroll down though and look at Silfuz

wheredoibegin · Post by **wheredoibegin** » Wed Feb 18, 2004 4:01 am

Ah well, easy come, easy go. It's probally better that there are no new heatsink matierials it would only encourage AMD and intel to put to it to good use.

Justin_R · Post by **Justin_R** » Wed Feb 18, 2004 10:02 pm

wheredoibegin wrote:It's probally better that there are no new heatsink matierials it would only encourage AMD and intel to put to it to good use.

The thermal conductivity of diamond can approach 6x that of silver. Other carbon structures, such as graphite foams and nanotube bundles, can also have thermal conductivities exceeding that of silver. This is a current area of research in materials science. Here is a company that is marketing a diamond/copper alloy with 2-3x the thermal conductivity of copper (about 2-2.5x silver). They seem to definitely be marketing to the computer heatsink industry.

lenny · Post by **lenny** » Wed Feb 18, 2004 10:22 pm

Coming soon to a store near you, Arctic Diamond heatsink compound!

I think water cooling is going to be significantly cheaper than exotic materials. Actually, since silver is really not that expensive, I'm surprised that nobody's selling a silver heatsink for the well heeled, erm, for lack of a better word, computer enthusiast.

Justin_R · Post by **Justin_R** » Thu Feb 19, 2004 12:11 am

lenny wrote:Coming soon to a store near you, Arctic Diamond heatsink compound!

Did you miss this on the page I linked?

Advanced Diamond Solution wrote:Heathru DiaPaste -- Advanced Diamond Solutions, Inc. now carries a breakthrough complementary diamond-based thermal interface product line to maximize the effectiveness of its DiaCu and DiaSil composite lines. Heathru DiaPaste [blah blah blah]

As for silver heatsinks, back before there were 80mm heatsinks, there was the Noise Control Silverado. Tom's Hardware gave it a glowing endorsement way back in March 2001. (I just happen to own one that I wound up never using. Incidentally, that roundup is classic Tom's Hardware, and I don't mean good classic.)

lenny · Post by **lenny** » Thu Feb 19, 2004 2:10 pm

Actually I was just poking a little fun at the Arctic Silver company. Not that I have any criticisms about their product (I use them).

Regarding the Silverado, why did you end up not using it? It looks like just a small silver disc (33g) attached to the bottom of a heat sink. Doesn't seem very efficient.

Did some rough calculations. A Zalman CNPS7000-Ag would weigh almost 900g, and cost $200 for the silver alone. A Zalman CNPS7000-AlAg would weigh 480g and cost $56 for the silver.

I guess only Ralf Hutter would be able to afford it with his "bottomless wallet"

(from a Sorbothane thread somewhere)

Justin_R · Post by **Justin_R** » Thu Feb 19, 2004 3:45 pm

lenny wrote:Regarding the Silverado, why did you end up not using it? It looks like just a small silver disc (33g) attached to the bottom of a heat sink. Doesn't seem very efficient.

I was running 2 noisy IBM drives and a noisy WD drive at the time, so swapping out my undervolted Golden Orb for the Silverado wouldn't have made much sense.

Gooserider · Post by **Gooserider** » Fri Feb 20, 2004 4:14 pm

There has been much discussion of Cu/Ag alloys on Procooling, and as noted it isn't useful stuff. It is SLIGHTLY better than Al as I recall, but not as good as pure Cu or Ag.

BTW, there is at least one semi-commercial Ag waterblock available - the "Cascade" jet impingement style block developed and made by Cathar of ProCooling fame is available in both Cu and Ag, albeit with a long wait at present. The Cascade is generally considered the top performing current design, and according to Cathar, the Ag version gives 1-2*C better temps on the same system than the Cu version.

There have also allegedly been some experiments with diamond based TIM pastes, which found they didn't work as well as expected. The theory is that the industrial diamond dust used had raggedly shaped particles, as opposed to the more uniformly shaped Ag particles in Arctic Silver etc. This meant that there were fewer molecules actually touching each other to transfer heat in the diamond paste, so the silver did better.

Gooserider