Power consumption of High Performance Computing (HPC) platforms is becoming a major concern for a number of reasons including cost, reliability, energy conservation, and environmental impact. High-end HPC systems today consume several megawatts of power, enough to power small towns, and are in fact, soon approaching the limits of the power available to them. For example, the Cray XT 5 Jaugar supercomputer at Oak Ridge National Laboratory (ORNL) with 182,000 processing cores consumes about 7 MW. The cost of power for this and similar HPC systems runs into millions per year.To further add to the concerns, due to power and cooling requirements and associated costs, empirical data show that every 10 degree Celcius increase in temperature results in a doubling of the system failure rate, which reduces the reliability of these expensive system. As supercomputers, large-scale data centers are meant to be clus-