Dual CPU nodes?

[Ken Chase]

On Mon, Oct 21, 2002 at 11:28:09AM -0400, Robert G. Brown's all...
 
> Most standard circuits have enough capacity to run two duals or four
> singles - you can estimate that they'll draw somewhere in the vicinity
> of 400-600 Watts, which is roughly a third the capacity of a twenty amp
> circuit for a switching power supply load, more like half the capacity
> of a 15 amp circuit.  Then you've got a monitor and network switch,
> which can be another 100-200 Watts.  A beefy UPS is not a bad thing to

wow. thats huge. I had 8 dual 2466s with 1.3tbirds on a 15Amp circuit (no
disk). When I moved it to a new building, I am guessing that the voltage was a
bit different, and the power bars they were wired into started blowing.
(perhaps they were drawing more amps at a lower voltage than my install
area?) At any rate, I put them in 8 per 20 amp circuit (instead of my
original intall 8/15) and nothing has blown (oh, and only 4 per power bar
too now :). Are you spec'ing for some seriously heavy disk power loads?

[A friend told me about blowing a circuit once at his lab and he had a large
 metal bracelet on. When the circuit blew, he was standing under the power
 run (about 5 feet over his head in the ceiling) and his bracelet shot up his
 arm and yanked on his wrist, quite hard! He had a bruise to prove it.  It
 was only a 20A circuit - what would cause that? Dangerous wiring situation?]

> For that reason you might well want to select systems based on their low
> power requirements rather than their speed...

Has anyone here actually done this based on a full TCO analysis where
operations cost were as large (or larger) a factor than initial install?
Are TMTA's worth it in this situ?

/kc


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> Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
> Duke University Dept. of Physics, Box 90305
> Durham, N.C. 27708-0305
> Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu
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-- 
Ken Chase, math at velocet.ca  *  Velocet Communications Inc.  *  Toronto, CANADA