Interesting People mailing list archives
IP: computer and telecom centers get undeserved black eye for power usage
From: David Farber <dave () farber net>
Date: Mon, 09 Apr 2001 08:53:58 -0400
X-Sender: dpreed () mail reed com X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 Date: Mon, 09 Apr 2001 08:46:56 -0400 To: farber () cis upenn edu From: "David P. Reed" <dpreed () reed com> Subject: computer and telecom centers get undeserved black eye for power usage Dave - Perhaps you and IP readers might find the following interesting. The NYTimes has managed to find "experts" that seem to think that the Internet can single handedly take down the power grid. The only problem is that no one seems to be checking their numbers... From NYTimes article by Jayson Blair (4/8/2001): "Con Edison engineers say they have been taken aback by the fact that the 46 server farms have asked for a minimum draw of 500 megawatts of electricity roughly the amount of power required by 500,000 homes." "The average data center consumes 60 to 100 kilowatts of electricity per square foot, compared with 6 to 8 kilowatts per square foot in an average commercial office building, said Tom Uhl, the project manager for Con Edison's telecom hotel team." This appears to me to be BULLS**T. It would be hard to stack computers and routers densely enough so that a 1x1x8 foot volume consumed 100 kW of electricity. Of course, the access space for humans around the equipment would have to be negligible as well, to achieve such densities in a building. What's interesting is that at the quoted numbers from Con Ed, even my 100 square foot office at Lotus would have been consuming 800 kW, being a commercial office building. I measured it back in 1988 for planning reasons (our architects needed data on what a building full of developers would need for power and A/C loads). I had two massive PCs and fluorescent lights in the office, plus some phones. The consumption during the workday was less than 400 W, or 0.4 kW, or a factor of **2,000** times less than these engineers are quoting for "ordinary commercial office space." To get 100 kW/sq. foot like the telecom hotels, they'd have to have the equivalent of about 1,200 1GHz PCs in that square foot, or about 120,000 such PC's in a space equivalent to my office. Now I know that Air Conditioning adds a power load, but A/C is pretty efficient, so I would presume that one could cool 1 Watt of equipment with at most a couple of Watts of power to the A/C (and that's being conservative). So maybe one would only have to put 40,000 PC equivalents in my old Lotus office to use that much power. Scaremongering at its best. I hope that someone checks their math. Seems to me that these power engineers (or the data center hotel architects/engineers) didn't do their homework. Or else I'm really wrong. - David -------------------------------------------- WWW Page: http://www.reed.com/dpr.html
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- IP: computer and telecom centers get undeserved black eye for power usage David Farber (Apr 09)