[90858] in North American Network Operators' Group
Re: WSJ: Big tech firms seeking power
daemon@ATHENA.MIT.EDU (Alex Rubenstein)
Sat Jun 17 00:50:33 2006
Date: Sat, 17 Jun 2006 00:50:04 -0400 (Eastern Daylight Time)
From: Alex Rubenstein <alex@nac.net>
To: Mikael Abrahamsson <swmike@swm.pp.se>
Cc: nanog list <nanog@merit.edu>
In-Reply-To: <Pine.LNX.4.62.0606170630560.19322@uplift.swm.pp.se>
Errors-To: owner-nanog@merit.edu
> What is the amount of energy coming out of a server as heat as opposed to
> what you put in as electricity? My guess would be pretty close to 100%, but
> is it really so? And I've also been told that you need approx 1/3 of the
> energy taken out thru cooling to cool it? So that would mean that to sustain
> a 100W server you really need approx 130-140W of power when cooling is
> included in the equation. Is this a correct assumption?
Based upon my real-world experience, and talking to a few folks, it's very
close to 100%. Most assume 100% for the practice of calculating cooling.
However, for those who are very scientific, they try to tell you that some
of the power is going into movement of hard drive heads, etc., which
creates force on your racks, etc. A true, but irrelevant discussion,
really, because it's likely an immeasurable amount.
One could do the excercise of putting a computer in a well insulated box
and measuring power in vs. rate of rise of temperature. Volunteers? :)
--
Alex Rubenstein, AR97, K2AHR, alex@nac.net, latency, Al Reuben
Net Access Corporation, 800-NET-ME-36, http://www.nac.net
