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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.
Of course they are wasting energy keeping it that cold. I am surprised the servers aren't frozen keeping it below 32 like that!
65 to 70 is plenty at my data center.
Yeah right, I'm not running a data center at 35 degrees C. People do have to go inside there and they shouldn't have to die from heat stroke. And, it would probably heat up any other rooms/offices it's next to.
If the owners of the building could run cooler I would think they would. Heat is expensive and building owners are cheap; if it is possible to spend less I would think that owners would.
"Maybe this world is another planet's hell"
Aldous Huxley
There is a flip side to the coin.... Higher inlet temperature can cause higher leakage current, resulting in lower efficiency. Some electricity extra will be lost to this effect. Also, in such conditions, thermal throttling can occur, reducing performance and particularly performance per watt, causing more energy to be required for same amount of work. Finally, there is some degree of longevity, which causes component failure ahead of expectations.
A way of getting the similar energy benefit without the risk would be something like what SuperMUC (http://en.wikipedia.org/wiki/SuperMUC) does: run water direct to the components. The problem is the upfront cost is generally not worth it except in places where energy costs are high enough to recoup that cost.
We looked for where the fibermap ran over a mountain range, and was near a hydroelectric plant. Our data center is cooled without chillers, simply by outside airflow 6 monhts of the year and with only a few hours use of chillers per day for another 3 months. I know this won'r help people running a DC in Guam, but for those who have a choice, locatiion makes a world of difference.
November 2012 Wired covers "hot" machine rooms in its paean to Google's data centers. Usually by the time they've picked up a story, it's done.
Vision with execution is hallucination.
I am bad in physics so I might say something stupid. But does it actually make a difference? I feel like the temperature of the hot components are WAY over 20C. So whatever energy they output is what you need to compensate for. In the steady state you need to cool as much as they heat. Isn't that constant whatever the temperature the datacenter is run at?
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.
Heat is death to computer hardware. Maybe not instantly, but it definitely causes premature failure. Just look at electrolytic capacitors, to name one painfully obvious component that fails with horrifying regularity in modern hardware. Fifteen years ago, capacitors were made with bogus electrolyte and failed prematurely. Some apparently still do, but the bigger problem NOW is that lots of items are built with nominally-good electrolytic capacitors that fail within a few months, precisely when their official datasheet says they will. A given electrolytic capacitor might have a design half-life of 3-5 years at temperatures of X degrees, but be expected to have 50/50 odds of failing at any time after 6-9 months when used at temperates at or exceeding X+20 degrees. Guess what temperature modern hardware (especially cheap hardware with every possible component cost reduced by value engineering) operates at? X+Y, where Y >= 20.
Heat also does nasty things to semiconductors. A modern integrated circuit often has transistors whose junctions are literally just a few atoms wide (18 is the number I've seen tossed around a lot). In durability terms, ICs from the 1980s were metaphorically constructed from the paper used to make brown paper shopping bags, and 21st-century semiconductors are made from a single layer of 2-ply toilet paper that's also wet, has holes punched into it, and is held under tension. Heat stresses these already-stressed semiconductors out even more, and like electrolytic capacitors, it causes them to begin failing in months rather than years.
Yes, it's generally in the nature of these companies to spend unneeded money. They hire people who's exact job is to make data centers' as efficient as possible. Even to the extent Facebook and others are open sourcing their information to try and get others involved to improve data center design. I say generally as I'm sure most seen the story on here recently over Microsoft wasting energy to meet a contract target, that however is a totally different kettle of fish.
And our customers (the telcos and enterprise) don't care enough about power savings for our management to pay me to work on it.
So our systems run with C-states disabled and no frequency/voltage stepping when idle.
The board of directors of the "Green Grid" is composed almost entirely of the companies that would benefit if data centers had to buy more computing hardware more frequently, rather than continued paying for cooling equipment.
Liberty in your lifetime
You can go a couple degrees warmer than in the "old days" (ten years ago). Things like bearings in fans and drives will fail. Capacitors will fail. Data centers produce LOTS of heat. I don't believe that the coin counters figured in the staff to replace the failed parts or the extra staff and time needed when manual procedures are used due to a downed system.
Computers crash/fail when overheating and in a datacenter that can happen very fast. You absolutely must keep the temperatures from getting too hot. Some datacenters can get away with minimal cooling. Some datacenters need chillers and tons of money invested in keeping things at a low enough temperature where computers wont randomly lock up on you from the heat. There must be some datacenters who have too much cooling but to say that datacenters in general dont need them demonstrates a lack of understanding what a datacenter is, that they are not all the same size nor is the hardware in them the same or all generating the same predictable temperatures.
http://interserver.net/
Therefore if you run hotter, the cooling of that hotter air or extraction to work is better.
Heat your company's hot water tank from the hot air from the server room and you save energy twice.