Power Usage Effectiveness or PUE, is the most commonly used metric in Data Centers today. Data Center industry organizations tout it, major companies brag about their scores, and energy efficiency certifications use it in their ratings.
Despite how thoroughly it has been embraced, though, it’s not without flaws. In my opinion, they mostly stem from the fact that PUE is more complicated than it looks. Although calculating the metric is a relatively straightforward exercise, the resulting score doesn’t tell you anything about the factors that influenced it. Hence why it’s a bad idea to compare PUE among Data Centers.