On Wed, 21 Jan 2009, Lux, James P wrote:
Without going into a big research project.. Here in Southern California,
rents are about $1/sq ft/month for cheap industrial space. Electricity is
about $0.20/kWh (maybe for a big bulk consumer, it gets down to the
$0.10/kWh range)
Figure a node draws 400w, and you can stack 20 nodes in a rack, which
occupies 10 square feet (need to have room to stand in front of the rack,
etc.)
So each node is costing $144/20= $7.20/yr in rent and 0.4*8000*0.2 = $640/yr
in electricity.
The rent is tiny compared to utilities. $2K/node seems plausible (3*
utility cost), but that doesn't include any of the infrastructure costs
(racks, cables, installation, copies of Windows Server edition, etc.). If
the real power draw is more like 200W, and you don't run them 24/7, then
you're getting down to the $100/yr/node costs..
But often you can't get "cheap" industrial space. You need excellent
climate control and server-room class wiring. Otherwise you can add the
cost of outfitting it with a couple of Lieberts, a harmonic-balancing
transformer, and a rewiring job (amortized however). Call it a few
hundred thousand over N years?
In server-class space, this is all provided but I doubt you'll get away
as cheaply as all that -- after all each node costs THEM an amortized
chunk of that same set of Lieberts and transformers. Also, may server
rooms offer "management" services -- somebody onsite to e.g. reboot your
nodes or babysite the power and AC while you sleep. This too adds cost.
So I think your estimate above is a lowball -- not implausibly low for
space that is "free" but you pay for power, but I'm guessing low by a
500-100% for a space you can just put your nodes in and not worry about
them (adequate space, security -- you've got tens to hundreds of
thousands of dollars of hardware in there and may have valuable data as
well, adequate AC and power, and maybe a systems admin qualified
babysitter.
rgb
Robert G. Brown Phone(cell): 1-919-280-8443
Duke University Physics Dept, Box 90305
Durham, N.C. 27708-0305
Web: http://www.phy.duke.edu/~rgb
Book of Lilith Website: http://www.phy.duke.edu/~rgb/Lilith/Lilith.php
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