Measuring energy efficiency in data centers

Energy efficiency in Data Centers (DCs) is currently becoming a topic of increasing importance, considering the rising prices of energy and the expansion of large data sets (Big Data) processing demand. A structured measurement framework that can be used to quantify energy efficiency is required to understand the opportunities for improving energy efficiency in DCs. In other words, a detailed analysis of energy metrics is needed. However, only a small step forward has been made in the measurement of DCs' energy efficiency in recent years. Therefore, the measurement of energy efficiency in DCs, through a set of globally accepted metrics, is an ongoing challenge. This chapter presents a comprehensive overview of the existing energy, thermal and productivity metrics for DCs and a critical analysis that investigates the intertwined nature of their action areas. The study provides a general methodology that can be used to measure the energy efficiency of DCs through a holistic approach in which the advantages and the disadvantages of existing and emerging metrics are considered critically