Trends in energy-efficient computing: A perspective from the Green500

A recent study shows that computation per kilowatt-hour has doubled every 1.57 years, akin to Moore's Law. While this trend is encouraging, its implications to high-performance computing (HPC) are not yet clear. For instance, DARPA's target of a 20-MW exaflop system will require a 56.8-fold performance improvement with only a 2.4-fold increase in power consumption, which seems unachievable in light of the above trend. To provide a more comprehensive perspective, we analyze current trends in energy efficiency from the Green500 and project expectations for the near future. Specifically, we first provide an analysis of energy efficiency trends in HPC systems from the Green500. We then model and forecast the energy efficiency of future HPC systems. Next, we present exascalar - a holistic metric to measure the distance from the exaflop goal. Finally, we discuss our efforts to standardize power measurement methodologies in order to provide the community with reliable and accurate efficiency data.