Note that the watt number on the power supply is DC output power, divide it=
 by the efficiency (80%?) to get the input power.

BUT: I have never seen a computer draw nearly as much power as the supply=
 can deliver.  The two i measured, an old 286 with 200W supply and double=
 height 5 1/4 drive, and a modern Celeron PC with "300W" supply consumed 60W=
 and 40W respectively.

I worked for a Power supply manufacturer and once we tested supplies from=
 another manufacturer at full load, and they blew after only a few hours! =
 They get away with it because no normal PC ever consume more than about=
 100W.  There is not enough cooling airflow in an normal PC anyway.  The=
 high power rating is a martketing trick.

However designing for high peak power is often the same as the supply is=
 stiff and stable against load spikes from the CPU, and I have seen some=
 docs claiming an athlom CPU needs a 300W power supply.  Naturally it is not=
 that it consumes the 300W...!
Technically they shold rate the peak load performenace, rather than=
 exaggregate the power rate.


BTW, Don=B4t forget the monitors and other equipment!

/Morgan

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