Power Consumption

[Madison Kelly]

Keep in mind that switching power supplies are not 100% efficient. They 
tend to be most efficient at around 75% of their maximum draw (225w draw 
on a 300w PSU). Even at that they tend to be 65% efficient (though the 
quality of your PSU could vary this a lot). Sooo... If even if you have 
peak efficiency drawing 225w with 65% efficiency you will be pulling 
roughly 300+w (someone correct me if my math is wrong).

The concept is there though, a 300w PSU draws more than 300w from the 
mains at 100% load.

Madison

Francois Ouellette wrote:
> I typically cut the rating in half, but for estimating a cost for 
> business purposes one tends to stay on the high side...
>  
>   François Ouellette
> <fouellet-cpI+UMyWUv9BDgjK7y7TUQ at public.gmane.org <mailto:fouellet-cpI+UMyWUv9BDgjK7y7TUQ at public.gmane.org>>
>  
>  
> 
>     ----- Original Message -----
>     *From:* Christopher Browne <mailto:cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org>
>     *To:* tlug-lxSQFCZeNF4 at public.gmane.org <mailto:tlug-lxSQFCZeNF4 at public.gmane.org>
>     *Sent:* Sunday, 14 August, 2005 20:42
>     *Subject:* Re: [TLUG]: Power Consumption
> 
>     On 8/14/05, *Francois Ouellette* <fouellet-cpI+UMyWUv9BDgjK7y7TUQ at public.gmane.org
>     <mailto:fouellet-cpI+UMyWUv9BDgjK7y7TUQ at public.gmane.org>> wrote:
> 
>         It definitely costs something!
> 
>         Looking at the added wattage of everything I have at home (2
>         desktops with
>         tube monitors, 1 laptop, router, printers, etc) it easily adds
>         up to over
>         2500 watts when many things are in use at the same time. This
>         costs easily a
>         few dollars every day.
> 
> 
>     It's not nearly as simple as that.
> 
>     Power supplies have to be rated for peak load, and, not unlike with
>     aircraft, that peak is normally required only for a brief period of
>     time, at start up time.
> 
>     Once the system is up, it likely consumes quite a lot less than the
>     300W that is the common rating for PSUs...
>     -- 
>     http://www3.sympatico.ca/cbbrowne/linux.html
>     <http://www3.sympatico.ca/cbbrowne/linux.html>
>     "The true  measure of a  man is how he treats  someone who can  do him
>     absolutely no good." -- Samuel Johnson, lexicographer (1709-1784)

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