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Green Grid Argues That Data Centers Can Lose the Chillers
Nerval's Lobster writes "The Green Grid, a nonprofit organization dedicated to making IT infrastructures and data centers more energy-efficient, is making the case that data center operators are operating their facilities in too conservative a fashion. Rather than rely on mechanical chillers, it argues in a new white paper (PDF), data centers can reduce power consumption via a higher inlet temperature of 20 degrees C. Green Grid originally recommended that data center operators build to the ASHRAE A2 specifications: 10 to 35 degrees C (dry-bulb temperature) and between 20 to 80 percent humidity. But the paper also presented data that a range of between 20 and 35 degrees C was acceptable. Data centers have traditionally included chillers, mechanical cooling devices designed to lower the inlet temperature. Cooling the air, according to what the paper originally called anecdotal evidence, lowered the number of server failures that a data center experienced each year. But chilling the air also added additional costs, and PUE numbers would go up as a result."
Tree huggers telling an IT manager it's OK for his servers to burn up so save a baby seal.
Well, Google has already started running their data center much warmer than many data centers of the past, apparently with no ill effect.
It has nothing to do with hugging trees, simply hard nosed economics. If 5 degrees induces 3 more mother board failures in X number of months and you already have the fail-over problem handled it only takes a few seconds on a hand held calculator to figure out that trees have nothing to do with it.
The rules were written, as the article explaines, based on little if any real world data, designed for equipment that no longer exists, built with technology long since obsolete. It was probably never justified, and even if it was back in thr 70s and 80s, it isn't any more.
Google and Amazon and others have carefully measured real world data talen from bazillions of machines in hundreds of data centers. They know how to do the math.
Sig Battery depleted. Reverting to safe mode.
I've been an operator and sysadmin for many years now, and I've seen this experiment done involuntarily a lot of times, in several different data centers. Trust me, even if you accept 35 C, the temperature goes well beyond that in a big hurry when the chillers cut out.
Well, Google has already started running their data center much warmer than many data centers of the past, apparently with no ill effect.
This is an understatement. Google increased the temp in their data centers after discovering that servers in areas with higher temps had fewer hard errors. So they went with higher temps across the board, saved tons of money on lower utility bills, and have fewer hard errors.
Back in the 1950s, early computers used vacuum tubes, which failed often and were difficult to replace. So data centers were kept very cool. Since then, data centers have continued to be aggressively cooled out of tradition and superstition, with little or no hard data to show that it is necessary or even helpful.
The article's central argument is that data centers can be run at higher temperatures. I'm pointing out that if you run your data center at higher temperatures to save on your energy costs, much or all of those savings could end up getting neutralized by premature equipment failure, and the cost of mitigating it.
Yet when Google analyzed data from 100,000 servers, they found failures were negatively correlated with temperature. As long as they kept the temp in spec, they had fewer hard errors at the high end of the operating temperature range. That is why they run "hot" data centers today.
I'll take Google's hard data over your gut feeling.