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Cooling Down Hot Processors
DonnaMai writes "Face it: the only scorching hot thing you want with a chip is salsa. Any other overheating is potentially counterproductive, and can be downright damaging to the microprocessor -- or other components. This article uncovers potential ways to chill the chips."
We already have that. It's called Speedstep and it's on Pentium M processors.
E = m c^3 Don't drink and derive E = m c^3
But, as the voltage levels drop, the leakage current through the transistors increases. At some point, dropping the voltage does not reduce the power. I think that we are pretty close to this point already.
"-1 Troll" is the apparently the same as "-1 I disagree with you."
It would --- but there would be other problems.
The first one is the most simple: silicon's expensive. Really expensive. The more units you can slice off that wafer the cheaper the units are. Making the die bigger simply for thermal reasons isn't going to wash with the chip manufacturers. They already glue the die to a metal backing plate, which gives you much the same effect anyway.
The second one, however, is the most crucial one. Electricity is slow. Electrical impulses travel at about 2/3 c through copper and a touch less through silicon (IIRC, I can't find the figures to check). This means that the bigger your die is, the longer it takes the impulses to travel from one side of it to the other.
A 1GHz clock fires every 10^-9 seconds; since the speed of light is 3x10^8 m/s, this means that the impulses are going to travel about twenty centimetres between clock pulses. For a 4GHz clock, it'll be about 5cm. There's a lot more wiring than that folded up inside the die; and it gets worse --- particular things happen at particular times throughout the clock cycle, and where you are in the clock cycle now depends on how long the wire is that connects you to the clock. Making sure everything happens in sync is a nightmare.
There are solutions to all of this; asynchronous designs which don't use clocks, offloading functionality to special-purpose processors like GPUs so you don't need as fast a main processor, radically different approaches like Cell, optical transports so you can route signals through each other, etc, but basically there are loads of good reasons why you need the die to be as small as humanly possible.