After having PUE and EUE foisted on us, I knew someone was eventually going to get it right. This article I just read is spot on for the right way to measure data center efficiency.
First, I’ll take a brief look back at The Green Grid’s PUE (power usage effectiveness) and the EPA’s EUE (energy usage effectiveness). PUE measures the ratio of power coming into the data center vs the power required to operate the IT equipment. EUE, the metric that the EPA is using to award Energy Star to data centers, measures the power all the way through the distribution grid from the generating station. Have a really efficient data center but you’re in a lousy place on the grid or a long way from the generator? You get a lousy EUE.
Both of these metrics are critically incomplete and that makes them ridiculously easy to game. Fire up a bunch of extra servers and just leave them idling and watch PUE and EUE come out great! Any efficiency metric that ignores how much actual work is being done for the energy consumed is worthless. This also leads facilities to erroneously being labeled polluters in the press. Polluting isn’t consuming lots of energy to get lots of work done, it’s consuming lots of energy to get little work done. Sort of like stating how much gas a car uses without saying how many miles it goes on that amount of gas, ridiculous.
According to the article, this software ties the value of the work being done directly to the underlying physical infrastructure supporting it. Finally, the last piece of the puzzle, not only from a power efficiency standpoint, but a business bottom line standpoint as well. Operating the data center inefficiently not only isn’t green, it kills the business economically as well (if you don’t want to go green for the sake of it being the right thing to do, then consider the effect on your wallet!).
The software authors say that “today’s power monitoring products focus only on the physical infrastructure, giving insight into how power is delivered to the data center but not insight into why it is being consumed”. They’re spot on, not only in terms of power monitoring, but the defective metrics data centers are being judged on.
Remember, efficiency is power in vs work out. If you’re not measuring both, you’re not measuring data center efficiency, period.
Vern, SwiftWater Telcom