[Epitope]

I have been reading a lot about high performance cpu cooling recently and I have constantly been asking myself why silver is not utilized more at the interface of the cpu and the cooling solution. It's obvious that some people spend big bucks on high performance (high heat) cpus and big bucks on cooling. Why don't manufacturers make a cpu with a silver heat spreader and why don't aftermarket cpu cooler manufacturers make coolers with a silver interface with the cpu?

I know this would be cost prohibitive for lower end cpus and coolers but what about high end applications. Since people are willing to spend $900 plus on an extreme edition processor I can't imagine an additional $50 penalty for a silver heat spreader edition being a deal breaker.

I would think that special edition 980X with a silver heat spreader would have you guys drooling. Is the cost penalty really that prohibitive? It seems like a very minimal amount of silver at this crucial location could make a significant improvement in performance.

 

[DuckieHo]

A silver heatsink will cost much more than additional $50.

Plus the benefits are relatively limited. A all copper TRUE costs how much more and provides 1C gain. A silver TRUE would cost much more and might result in another 1C.

For that, get a phase unit or at least water cooling.

 

[H-man]

Silver tarnishes.

 

[Chunky_Chimp]

Quote:

Originally Posted by DuckieHo A silver heatsink will cost much more than additional $50. Plus the benefits are relatively limited.

Yup.

 

[Epitope]

Quote:

Originally Posted by Idiot Silver tarnishes.

So does copper. Copper has to be coated or else it turns green (patina) very quickly.

 

[BeDuckie]

Even if they threw in a stock silver heatsink I'd still throw it away.

 

[losttsol]

Yes, it is cost prohibitive

Silver = ~$22/ounce
Copper = ~$0.22/ounce

Copper is a hundred times cheaper. That is your answer.

When you're making millions of units of something, that difference adds up quick.

 

[Epitope]

Well I did a little google searching and while I can't find info on the thickness of the i7 heat spreader it appears the core 2 duo spreader is about 1.7mm thick.

The official widths of the heat spreader are 36.6mm x 39.1mm. Assuming the spreader is also 1.7mm thick thats

0.17 x 3.66 x 3.91 = 2.43 cubic centimeters of metal needed.

Silver has a density of ~10.5 grams per cubic centimeter.
http://www.24carat.co.uk/densityofgo...talsframe.html

Thats 25.5 grams of silver needed to make the heat spreader.

25.5 grams = 0.9 ounces (0.899 ounces)

The heat spreader would not need more than $20-30 worth of silver.

Silver has ~%10 better thermal conductivity than copper. I still don't understand why it is not an option on a $1000 cpu. It's worth the cost in my opinion.

 

[BlackHoleSon]

Cost and tarnish, and it's incredibly soft. If it gets very hot and its soft, bad for flatness.

 

[DuckieHo]

Quote:

Originally Posted by Epitope Well I did a little google searching and while I can't find info on the thickness of the i7 heat spreader it appears the core 2 duo spreader is about 1.7mm thick. The official widths of the heat spreader are 36.6mm x 39.1mm. Assuming the spreader is also 1.7mm thick thats 0.17 x 3.66 x 3.91 = 2.43 cubic centimeters of metal needed. Silver has a density of ~10.5 grams per cubic centimeter. http://www.24carat.co.uk/densityofgo...talsframe.html Thats 25.5 grams of silver needed to make the heat spreader. 25.5 grams = 0.9 ounces (0.899 ounces) The heat spreader would not need more than $20-30 worth of silver. Silver has ~%10 better thermal conductivity than copper. I still don't understand why it is not an option on a $1000 cpu. It's worth the cost in my opinion.

A silver stock heatsink would still perform worse than an aftermarket heatsink. Design is more important than material.

10% better thermal conductivity does not mean 10% better. Copper is 60% more thermal conductive than aluminum. An all copper TRUE barely outperforms an aluminum fin TRUE.

 

[Epitope]

Quote:

Originally Posted by BlackHoleSon Cost and tarnish, and it's incredibly soft. If it gets very hot and its soft, bad for flatness.

Copper also tarnishes, thats why the heat spreader is nickel plated. You could also plate the silver. The plating is so thin is has little effect on the performance.

 

[Epitope]

Quote:

Originally Posted by DuckieHo A silver stock heatsink would still perform worse than an aftermarket heatsink. Design is more important than material. 10% better thermal conductivity does not mean 10% better. Copper is 60% more thermal conductive than aluminum. An all copper TRUE barely outperforms an aluminum fin TRUE.

I'm pretty sure the heat pipes and base on the TRUE are copper in either version. The fins are made of different materials. Thats a little different considering how far away from the heat source those are. I'm talking about just the interface of the cpu and cooling solution. This is where 100% of the heat must pass through. I think any improvement in this area would increase the efficiency of whatever cooling solution is utilized.

I'm sure a silver finned TRUE wouldn't perform a whole lot better than an aluminum one either.

 

[tmunn]

Interesting thread, this.

Quote:

Originally Posted by Epitope The heat spreader would not need more than $20-30 worth of silver.

So let's say $25 worth of raw silver. Then they would have to get that silver machined into the IHS form(which I'm sure they outsource). Assuming they are only going to make a limited number of CPUs with this special IHS, they are going to have to pay a hefty premium to the IHS makers for such a small run. So let's say that it will cost an extra $100(I think this may be too modest, but anyway) for this special chip. Is it worth it? Maybe for a very few select enthusiasts. It might be worth emailing Intel about this? You never know.

I think we would be better served if

a) They made the IHSs flat.

b) They used a high quality TIM between the chip and IHS.

 

[thefreeaccount]

It's not a bad idea IMHO. If you made it, I'm sure someone would buy it.

 

[Blameless]

I'd rather see consumer CPUs sold without heatspreaders.

Sure would save me a lot of sanding.

Quote:

Originally Posted by Idiot Silver tarnishes.

So does copper.

Answer is the same, nickel plating.

Quote:

Originally Posted by BeDuckie Even if they threw in a stock silver heatsink I'd still throw it away.

I hope you mean melt it down.

Quote:

Originally Posted by BlackHoleSon Cost and tarnish, and it's incredibly soft. If it gets very hot and its soft, bad for flatness.

It obviously wouldn't be pure silver, but alloyed with copper. It would be hard enough.

Quote:

Originally Posted by tmunn b) They used a high quality TIM between the chip and IHS.

The IHS of most modern CPUs is soldered to the heatsink. The solder has better thermal conductivity than most any non-metal TIM, and more importantly, is very durable.

 

[Dirtyworks]

It isn't done mainly for the cost vs performance ratio. Copper does more than good enough and costs significantly less, as said earlier.

Though silver DOES tarnish, the tarnish doesn't impede thermal/electrical conductivity- like the tarnish on copper does. And though pure silver will get hot when used as a heatsink, I don't think even 100c would be enough heat to allow it to be malleable enough for what you're implying.

tl;dr
Cost vs Performance ratio is why.

 

[ghost55]

for the cost of a silver heat spreader, you could just go and use phase change or water cooling