Stewart Stremler wrote:
Because you'd get finer control over what parts of the chip are
getting cooled, and when?
Unlikely. You need a reasonably sized thermal interface to make any
impact. Peltier's work only because they can move heat in steady-state
faster than a microprocessor can produce it in steady-state.
And that doesn't even begin to consider what dumping bismuth and
tellurium into your fab line would do. Most room temperature Peltiers
are Bismuth Telluride.
Peltier devices don't just magically make things cool. They have to
ship that heat somewhere. And, BTW, Peltier devices also *generate*
quite a bit of heat by themselves. For every amount of heat they move,
they generate about 4x more heat of that same amount.
Well, they aren't very efficient... :)
Not even slightly. They have their uses, but efficient heat transfer
isn't one of them.
Yes. But if it's getting dumped into a heatsink eight inches (or eight
feet) from the actual chip, it's somebody else's problem.
Not really. You are solving the wrong problem. Moving heat is really easy.
Getting rid of the heat, ah, now there's the problem ...
The real problem, as I see it, is that there's a max temperature
difference limiting things. What I *really* want is a thermal
superconductor... but that comes of rereading Niven recently, I
think.
In what way does copper not meet that specification? Copper really does
dissipate heat very evenly, very quickly throughout the metal. It's not
a superconductor, but compared to the ability of the microprocessor to
conduct heat (silicon and silicon dioxide are not very good conductors)
and the ability of air to remove heat, it might as well be.
The issue in heat dissipation isn't the microprocessor to heatsink
interface. That works *just fine*.
The issue is the heatsink to air interface. Air *sucks* as a thermal
conductor. If you didn't have to put the heat into the air to get rid
of it from the copper heatsink, life would be good.
Everybody forgets the fact that the advantage to water cooling *isn't at
the microprocessor*. The advantage is that you can take all that heat
and move it to some big, honkin' radiator somewhere.
-a
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