A Case Study and Critical Assessment in Calculating Power Utilisation Effectiveness for a Data Centre

This paper examines the metrics commonly used to assess the energy efficiency of data centres through performing and critiquing a case study calculation of energy efficiency. Specifically, the energy efficiency metric Power Usage Effectiveness (PUE), which has become a de-facto standard within the data centre industry, will be assessed. This is achieved by using open source specifications for a data centre in Prineville, Oregon, USA provided by the Open Compute Project launched by the social networking company Facebook. The usefulness of the PUE metric to the IT industry is critically assessed and it is found that whilst it is important for encouraging lower energy consumption in data centres, it does not represent an unambiguous measure of energy efficiency.