Using the Greenup, Powerup, and Speedup metrics to evaluate software energy efficiency

With recognizing power as a first-class citizen in the HPC community and the growth of software running on battery-driven devices, the need to evaluate software design based on the combined effects of energy and performance has become eminent. Despite of the numerous metrics to evaluate software performance, the study on how to evaluate software energy efficiency is still in its early stage. In this paper, we propose the Greenup, Powerup, and Speedup metrics (GPS-UP) to categorize software implementation and optimization efficiency. The GPSUP metrics transform the performance, power and energy of a program into a point on the GPS-UP software energy efficiency quadrant graph. We present eight categories of possible scenarios of software optimization, with examples on how to obtain them. Four categories are green (save energy), and four are red (waste energy). Moreover, we compare our metrics to existing metrics such as Energy Delay Product (EDP).