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Power Usage Effectiveness

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Data centers are getting more energy efficient because their clients are looking for “green” host providers. That is, energy efficiency is being reduced to yet another economic advantage over the competition.

I’ve had the opportunity to visit a data center today together with 19 students and the tour was pretty impressive. It wasn’t my first visit, but it was the first one where my inner eyebrows were raised more than once. A sleek presentation on availability and category tiers—where certification and more big money of course is involved—also introduced us to the concept of PUE, or Power Usage Effectiveness.

The calculation is simple: total power usage of the facility divided by IT equipment power gives you a number between 1.0 and 2.0—say 1.3. That means an energy loss of 30%, usually due to heavy energy investments into climate control. Apparently, a PUE of 1.3 is pretty good. Clients usually ask for a PUE: the lower, the more chance of gaining a contract.

A PUE of 1.1 means less power waste, which is good, right? But at the meantime, we also learn that physical racks within the data center shrink in size. In other words, hardware is getting slimmer and smaller. Great! That means we can stuff more racks in the same physical room, without compromising our PUE (too much, since more smaller hardware not necessarily means less heat dissipation).

My uneducated brain tells me simply looking at a PUE number is like closing your eyes for the real problem: climate change. Even if companies manage to build super efficient data centers with PUEs of 1.0—good job!—we’re still massively and terrifyingly fast pushing towards more hardware and more data centers, ergo more power usage globally.

Why does the Chinese government require one of the biggest data centers in the world just to spy on people? 200 exaflops of data by 2023. Exawhat? Flops? Like floppies, 1.44 MB? I can’t even begin to fathom how much that is, or how huge those data centers must be. Or how much of my data is stored somewhere; whether it’s the local data center I visited (local banks, government, …) or global centers like Google’s or Amazon’s. It feels like my existence somehow is part of the problem. I take up gigabytes—and generate CO2— without knowing or wanting it.

Why does your fridge require an internet connection? Why does your doorbell need to retain data in the cloud? Why does your central heating control unit absolutely has to be controlled from your smartphone through an app? Does it really? Why do our solar panels upload “anonymous” data to a dubious Chinese server? Why would we need to store 4K—and within a few years, 8K—videos of stupidly goofing around on Twitter/Instagram/TikTok/whatever? Or even worse, why does everyone suddenly need a networked security camera?

I know some people call me an old fart when I rant about this. Utterances like “But you work in IT, why don’t you simply embrace it?” (exactly because I work in IT!) or “But it’s the next best thing!” (you clearly haven’t given it any thought) don’t exactly help.

Can we please stop this madness? Not everyone benefits from “a cloud”, not all problems should be fixed by throwing things in “the cloud”. In supermarkets, some food packets contain a nutritional label; from a green A (healthy) to a dark red F (o-ow). Maybe we should start applying that on sites and services we use to identify useless power consumption.

Today, I left the data center feeling genuinely scared. Words like metrics and big data frivolously scattered throughout presentations made me want to run. But I have no idea where to…

tags icon data centers energy

I'm Wouter Groeneveld, a Brain Baker, and I love the smell of freshly baked thoughts (and bread) in the morning. I sometimes convince others to bake their brain (and bread) too.

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