tm_wanka@earthling.net (Thomas Michael Wanka) writes:
> I may be wrong, but from what I heard and experienced, the power supply of 
> (at least many i386 architectures) will not consume less power if the cpu is 
> idle. I had special power supplies, that detected the consumption of the PC 
> (that is cpu, harddrives etc.) and if possible would lower the consumption to 
> about 30W. Possibly the ATX powersupplies act different here.

Desktop machines consume so much power that it is hard to see the
power savings when measuring the current of the power supply.  One can
see the savings by seeing the CPU's temperature drop, but even on a
power hungry desktop CPU thats probably only a 10watt change out of a
total of 150watts or so.  It is hardly going to lower one's electric
bill.

Laptops on the other hand are fairly strapped for power.  Everything
is designed to be so low power that any power the CPU uses will be
noticed greatly.  My sony 505tx vaio has a very meager 16 Watt-hour
battery.  With a halt in the idle loop and running X and emacs (but no
cpu hogs) the unit uses around 5 watts of power for a 3 hr runtime.
Running the-evil-os-of-redmond which does a spin-loop for its idle
loop the unit uses ~10 watts giving only a ~1.5hr runtime. (snicker)
Thats a 2x power savings just for halting.

-wolfgang
-- 
       Wolfgang Rupprecht <wolfgang+gnus@dailyplanet.wsrcc.com>
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