UNDERSTANDING PUE
Power usage effectiveness ( PUE ) is a ratio used to determine how efficiency a data centre uses energy . The metric was originally developed by the Green Grid consortium and first published as a methodology in 2016 . A data centre running at 100 % efficiently would have a PUE of 1 . Currently , the industry standard for data centres is a PUE of around 1.67 .
Largely , PUE is agreed upon to be a useful way to measure the efficiency with which a data centre consumes energy . However , it ’ s worth noting that a low PUE can sometimes be misleading if used as the sole measurement of a data centre ’ s sustainability .
Paul Nelson , strategist and director at Hewlett Packard Enterprise , notes that PUE is greatly affected by “ exterior and interior factors ,” adding that a data centre ’ s PUE is “ relative and varies over time ” due to factors like IT utilisation , environmental factors like the time or year or current weather , the hardware used to cool the data centre , and stage of the data centre in its build out .
“ The only problem with using PUE as a metric is that there is more than one way to calculate it , making it difficult to compare one facility with another ,” notes Johnson , positing that , “ What is needed are performance metrics that are more holistic than PUE in measuring data centre efficiency . The key limitation of PUE is that it measures the overall efficiency of an entire building infrastructure supporting a given data centre , indicating nothing about the efficiency of the IT equipment itself . IT efficiency , on the other hand , is the total IT output of a data centre divided by the total input power to IT equipment .”
53 datacentremagazine . com