An analysis of the power usage effectiveness metric in data centers

During the last decades the growing demand for computer infrastructures and software has led to important increased in the number and the dimension of data centers. The energy used by the data centers (here are included the power for IT equipment and the power for the cooling infrastructure) has increased dramatically. The paper proposes an analysis of Power Usage Effectiveness (PUE), the classical metric for measuring energy efficiency in Data Centers (DC). A discussion of its advantages and of its shortcomings is presented. Some complementary metrics and new metrics for improving PUE are synthesized. This analysis can help researchers to identify the main trends of Energy Efficiency assessment in DC.