what kind of UPS will work best?

Gary Kline kline at tao.thought.org
Mon Oct 8 10:10:52 PDT 2007

On Mon, Oct 08, 2007 at 02:36:05AM +0200, Pieter de Goeje wrote:
> On Sunday 07 October 2007, Gary Kline wrote:
> > 	First, thank to both you and Bart for your cmments.  You were
> > 	*right* about the price.  Can I assume that a ballpark would be
> > 	400W for each server?  (My wife is right: I've got to cut back to
> > 	three computers:-)  I've found one APC 2200VA with a 17minute
> > 	uptime.  3 times 400W, yes?
> I think this is overkill. Some time ago I was wondering the same thing and to 
> verify my guess on the overall power usage of my servers I bought a VA/Watts 
> meter (EUR. 39,-). Turns out average wattage is about 90watts per server idle 
> and max 130watts under load. On powerup they will use a max. of 180watts for 
> less than a second. The servers are simple dual cores with about 2 harddisks 
> each. (no screens or other devices attached) Also, the powerfactor was ~0,95 
> so that means that for every Watt of apparent power (VA) almost a Watt of 
> real power was used. Thus, for my servers I would need something like a 
> 500Watt/600VA UPS.
> So my advice is: don't guess but measure.

	Thanks a lot.  I was thinking of doing something like this;
	maybe an ammeter to see how much power each server draws; then
	(possiibly add a bit for reserve).  

	I'm looking at this as a long-time project.  Not rushing to do
	something completely foolish.  So the more accuracy, the better!


> Cheers,
> Pieter de Goeje
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  Gary Kline  kline at thought.org   www.thought.org  Public Service Unix
      http://jottings.thought.org   http://transfinite.thought.org

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