Glossary
PUE
Power usage effectiveness, the ratio of a data center's total energy use to the energy used by its computing equipment.
Power usage effectiveness (PUE) divides all the energy a data center uses by the energy that reaches its servers and other IT equipment. A PUE of 1.0 would mean every unit of power goes to computing; anything above that goes to cooling, power conversion, lighting, and other overhead.
Operators cite PUE to show efficiency. A lower number is better.
PUE says nothing about how much computing work gets done, how clean the electricity is, or how much water the site uses. A very efficient building can still use a great deal of power in total.
Read more: our explainer