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Companies Waste $2.8 Billion Per Year Powering Unused PCs
snydeq writes "Unused PCs — computers that are powered on but not in use — are expected to emit approximately 20 million tons of CO2 this year, roughly equivalent to the impact of 4 million cars, according to report by 1E and the Alliance to Save Energy. All told, US organizations will waste $2.8 billion to power 108 million unused machines this year. The notion that power used turning on PCs negates any benefits of turning them off has been discussed recently as one of five PC power myths. By turning off unused machines and practicing proper PC power management, companies stand to save more than $36 per desktop PC per year."
That's why I use hibernation. It takes one minute to shutdown and another to startup.
The computers are not being left *solely* for the purposes of the cluster. The policy of the university admins is to leave them overnight for updates, and anyway the users don't like to turn them off (so they don't have to wait for the computer to boot up in the morning). Therefore we are utilising what sits there idle anyway. Furthermore, anyway you don't take into account the overhead of buying a supercomputer / cluster with 1000+ nodes in the first place -- and we are utilising what has already been payed for (both in terms of money from the university and in terms of energy used / CO2 emission that took to produce the units). Finally, buying a supercomputer / cluster is, due to the necessary bureaucracy involved in expensive investments, a major pain in the ass and also a system-administrative effort.
Of course, this solution cannot replace a proper cluster -- I have already outlined why, and also I agree with you in puncto efficiency. But if you have a bunch of PCs sitting around idle at night, and need calculations -- this may be a cheap and quick solution.
j.
28.8 billion kWh/year is more than enough to 'change the power plants operating conditions'. A 125 MWe unit (the output of one generator of a nearby power station) delivers about 1 billion kWh/y, so shutting down all PCs at night would make a significant dent in the base load.
Why "5 minutes"? I would guess that if you turn off PCs after the workday and don't turn them back on until the next morning you save more like 15 to 16 hours of run time.
That's 960 minutes per day x 230 work days = 220,800 minutes. Or 3,680 hours per desktop per year. That's not counting in the 48 hours every weekend (52) which equals an additional 2496 hours, plus however many holiday days at another 24 hours each. If there are seven for whatever business, that's another 168 hours. And if the worker takes off two weeks each year, that's an additional 336 hours.
Grand total is 6,680 hours of wasted run time as an estimate.
For the people who run the fancy screensavers, the power used is fairly large. A blank screen is the best. That lets the monitor go into low power.