Topics on measuring real power usage on high performance computing platforms

Power has recently been recognized as one of the major obstacles in fielding a Peta-FLOPs class system. To reach Exa-FLOPs, the challenge will certainly be compounded. In this paper we will discuss a number of High Performance Computing power related topics. We first describe our implementation of a scalable power measurement framework that has enabled us to examine real power use (current draw). [Using this framework, samples were obtained at a per-node (socket) granularity, at frequencies of up to 100 samples per second.] Additionally, we describe how we applied this capability to implement power conserving measures on our Catamount Light Weight Kernel, where we achieved an 80% improvement. This ability has enabled us to quantify the amount of energy used by applications and to contrast application energy use between a Light Weight and General Purpose operating system. Finally, we show application energy use increases proportionally with the increase in run-time due to operating system noise. Areas of future interest will also be discussed.