Power use of disk subsystems in supercomputers

Exascale will present many challenges to the HPC community, but the primary problem will likely be power consumption. Current petascale systems already use a significant fraction of the power that an exascale system will be allotted. In this paper, we show measurements for real I/O power use in three large systems. We show that I/O power use is proportionally fairly low per machine, between 4.4 and 5.5% of the total consumption. We use these measurements to motivate a burst-buffer checkpointing solution for power-efficient I/O at exascale. We estimated this solution to use approximately 6.6% of the exascale machine power budget, which is on par with today's systems.