Power Reduction Techniques For Microprocessor Systems
Power consumption is a major factor that limits the performance of computers. We survey the “state of the art” in techniques that reduce the total power consumed by a microprocessor system over time. These techniques are applied at various levels ranging from circuits to architectures, architectures to system software, and system software to applications. They also include holistic approaches that will become more important over the next decade. We conclude that power management is a multifaceted discipline that is continually expanding with new techniques being developed at every level. These techniques may eventually allow computers to break through the “power wall” and achieve unprecedented levels of performance, versatility, and reliability. Yet it remains too early to tell which techniques will ultimately solve the power problem.
Computer scientists have always tried to improve the performance of computers. But although today’s computers are much faster and far more versatile than their predecessors, they also consume a lot of power; so much power, in fact, that their power densities and concomitant heat generation are rapidly approaching levels comparable to nuclear reactors. These high power densities impair chip reliability and life expectancy, increase cooling costs, and, for large data centers, even raise environmental concerns.