The Green Grid is an association of IT professionals seeking to dramatically raise the energy effi ciency of datacenters through a series of short-term and long-term proposals. This is an update to the very fi rst white paper published by the Green Grid in February 2007 called “Green Grid Metrics: Describing Data Center
Power Effi ciency” to refi ne the nomenclature and intent of that paper. In that paper, The Green Grid proposed the use of Power Usage Effectiveness (PUE) and its reciprocal, Datacenter Effi ciency (DCE) metrics, which enable datacenter operators to quickly estimate the energy effi ciency of their datacenters, compare the results against other datacenters, and determine if any energy effi ciency improvements need to be made.
Since then PUE has received broad adoption in the industry but DCE has had limited success due to the misconception of what data center effi ciency really means. As a result, this paper re-affi rms the use of PUE but redefi nes its reciprocal as datacenter infrastructure effi ciency (DCiE). This refi nement will avoid much of the confusion around DCE and will now be called DCiE.
In the long term, The Green Grid is developing metrics to measure data center productivity as well as effi ciency metrics for all major power-consuming subsystems in the datacenter. To promote these metrics and drive greater datacenter energy effi ciency for businesses around the world, The Green Grid will publish future white papers that provide detailed guidance on using these metrics. We will also continue to collaborate with organizations such as the EPA, ECMA and Climate Savers that promote a similar goal and vision.