Energy Proportionality and the Future: Metrics and Directions

This paper proposes a pair of quantitative metrics, namely the idle-to-power ratio (IPR) and the linear deviation ratio (LDR), to be used together for measuring the energy proportionality of computing systems. The metrics are applied to the publicly available SPECPower_ssj2008 benchmark results, yielding a partly grim trend of energy proportionality, which has to be addressed and possibly rectified by the computer industry. The paper also proposes future research directions on studying the effects of energy proportionality on software-based energy-saving techniques.