Quantifying the Energy Efficiency Challenges of Achieving Exascale Computing

Power and performance are two potentially opposing objectives in the design of a supercomputer, where increases in performance often come at the cost of increased power consumption and vice versa. The task of simultaneously maximising both objectives is becoming an increasingly prominent challenge in the development of future exascale supercomputers. To gain some perspective on the scale of the challenge, we analyse the power and performance trends for the Top500 and Green500 supercomputer lists. We then present the PαPW metric, which we use to evaluate the scalability of power efficiency, projecting the development of an exascale system. From this analysis, we found that when both power and performance are considered, the projected date of achieving an exascale system falls far beyond the current target of 2020.