Demystifying energy consumption in Grids and Clouds

Energy efficiency in large-scale distributed systems has recently emerged as a hot topic. This paper addresses some theoretical and experimental aspects of energy efficiency by putting in perspective some assumptions made in this domain and some observations and analyses. Based on some experimental results and measurements, we revisit and focus on some “truths” commonly assumed concerning the energy usage of servers, the links between resource load and consumed energy, the impact of ON/OFF models, and some wrong assumptions linking energy and virtualization.