[geeks] New Intel Atom-based barebones system

[Jonathan Groll]

On Sat, Aug 16, 2008 at 03:11:14PM +0000, wa2egp at att.net wrote:
> > It would be most interesting to know if these power consumption
> > figures tally up with those reported by an ammeter or kill-a-watt at
> > the wall. Do they?
> > 
> > Obviously we can expect some power loss from the PSU, but otherwise it
> > would be a good test of the accuracy of the onboard sensors.
> > 
> 
> I don't think so.  My Ultra 80 draws about 120 watts on the average which is far lower than figures presented.  Mine is measured not gleaned from the numbers on the power supply label.
> My son's latest PC draw <200 watts and he loaded it up.

Some figures from my machines (*):

Ultra 60 with 2 SCSI disks = 130VA
Atom D945GCLF with 3 SATA disks = 50VA (up to 55 under load)
Prescott P4 with ATI graphics = 115VA (up to 175 when under load)

Oddly enough, the U60 draws roughly the same amount of current whether
it's under load or not! The Atom measurement is with a regular
desktop ATX power supply - but I plan to use an M2-ATX DC-DC PSU later
on.

Cheers,
Jonathan.

(*) Not sure of the accuracy of these measurements, and wouldn't mind
some comments on my rather unorthodox method of measurement from a few
of the more picky members of this list (I am not an electrical
engineer!) My rather cheap multimeter only measured DC A, and I didn't
have an appropriate sized shunt resistor at home, so I built a bridge
rectifier from some diodes that I had lying around and measured the DC
current draw. I'm surprised it even worked, as computer power supplies
are rated only to accept AC?!