[103237] in North American Network Operators' Group
RE: rack power question
daemon@ATHENA.MIT.EDU (John Curran)
Sun Mar 23 13:39:17 2008
In-Reply-To: <002401c88d09$50382ce0$660a0a0a@oneunified.local>
Date: Sun, 23 Mar 2008 13:37:28 -0400
To: "Ray Burkholder" <ray@oneunified.net>
From: John Curran <jcurran@mail.com>
Cc: <nanog@nanog.org>
Errors-To: owner-nanog@merit.edu
At 2:14 PM -0300 3/23/08, Ray Burkholder wrote:
>My desktop has a 680 Watt power supply, but according to a meter I once
>connected, it is only running at 350 to 400 Watts. So if a server has a
>980W power supply, does the rack power need to be designed to handle
>multiples of such a beast, even though the server may not come close
>(because it may not be fully loaded with drives or whatever)? Wouldn't it
>be better to do actual measurements to see the real draw might be?
Yes, if you perform the measurements both at peak cpu load
and during power-up (quite a bit of well-known gear maxes
out its power draw only during the power-on sequence).
Also, you're still going to want to size the power drop so that
the measured load won't exceed 80% capacity due to code.
/John
