Metrics and an Infrastructure Model to Evaluate Data Center Efficiency

This work describes two data center efficiency metrics: Power Usage Effectiveness (PUE) and Compute Power Efficiency (CPE). PUE characterizes the fraction of the total data center power used for IT work. CPE characterizes the overall data center efficiency, considering IT equipment utilization as well as how power is used in the data center. The PUE results from three data center studies are presented here. The data suggests that a carefully designed and managed data center has a PUE of 2.0. More studies are required to determine the range of values for the typical data center. A data center infrastructure and energy cost model is presented to compare hardware costs to infrastructure and energy costs. The impact of PUE on these costs is examined to illustrate the impact of data center efficiency on the total cost of operating a data center.