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Re: Energy consumption vs % utilization?


From: David Lesher <wb8foz () nrk com>
Date: Tue, 26 Oct 2004 20:12:46 -0400 (EDT)


Speaking on Deep Background, the Press Secretary whispered:


You should be able to pick up simple current / wattage meter from local 
hardware store for $20 or so. That will tell you that on a modern 
dual-CPU machine the power consumption at idle CPU is about 60% of peak. 
The rest is consumed by drives, fans, RAM, etc. As wattage the 
difference is 100-120W (50-60W per cpu)

Bogus data alert....

A ammeter will tell you amps. But in the world of switcher power
supplies, that does not beget watts. [Why? is an exercise for
the student. Start with "power factor" and "VARS" and worry about
asymetric loads...] 

If you want to talk watts, as you must to worry about HVAC,
or really watt-hours... acquire a power company type meter - in
glass with a whirlygig. Put it in a meter box with plugs. [See
your local eletrical wholesaler..]

(The rotating disk watthour meter is amazingly accurate under
almost any kind of load waveform. Only time-of-day metering has
spurred the utilities to replace them.)

Plug the machines into it; it into the wall. Note the numbers
and the time, and come back in 24Hours. 




-- 
A host is a host from coast to coast.................wb8foz () nrk com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433


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