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Attacking Abuses of Power – Part 1
(Bryon Moyer)
It’s the era of energy. Look at the newspaper and see how many stories ultimately relate to energy. Oil and gas prices are up. Natural gas is no longer a cheap alternative to electricity. Energy companies teach the world that some of them can’t be trusted to operate in a “free” market. Nuclear is given another look. Coal is marketed as “clean.” Food prices go up in parts of the world as food competes with ethanol for grain. Cellulosic ethanol. Biodiesel. Hybrids. Some would argue that a war is being fought over energy. Global warming/climate change. The growth of social awareness of things “green,” ultimately leading to political awareness and sometimes even action.
Within the completely independent realm of semiconductor technology, transistors at the 90-nm and smaller nodes are burning more power. Dynamic power goes up as clock frequencies increase; static power increases as sub-threshold leakage grows, to the point where, at high temperatures, the leakage current can completely dominate the overall current draw of a large chip. This heat increases cooling requirements and reliability concerns. It raises economic concerns if racking and fan requirements grow. A single PC will still survive plugged into your wall, but a roomful of servers will be in a world of hurt if the power demands keep ratcheting up.
It’s unusual when socio-political, technology, and economic requirements converge, but that’s certainly happening now. Regardless of your economic standing, your politics, or your involvement with technology, anyone can find a good reason to reduce power. And while power has typically been traded off against other needs, that need not always be: sometimes a better design yields higher performance, lower area, and lower power. In the past, speed and area have taken top billing; no longer, as was made evident, in black and white, on a simple technology trends slide in an Intel presentation: “Power is the limiter.” [more]
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