Practical Data Center Power Proportionality

Energy accounts for a significant fraction of the operational costs of a data center and data center owners are increasingly interested in moving towards power proportional designs. However, we show that current power proportional solutions are inherently limited in the energy savings they can offer; the reason is that they focus on managing the data center IT equipment (disks, servers) and neglect the large power overheads resulting from non-IT infrastructure such as cooling, and power distribution equipment. We propose a solution, where the power management unit is as large as a rack, or even an entire containerized data center. We show that it is practical today to design data centers to power down idle racks or containers – and in fact, current online service trends strongly enable this model. Finally, we show that energy savings increase by an order of magnitude with larger power management units, while performance remains unaffected.