I have an overclocked Opteron 175 at 2.64GHz running at 1.475 volts and idles around 39C.
Benchmarking jumped faily significant according to FutureMark results ~ 4,335 to 5,048 3DMarks06 and 9,000 to 10,100 marks using 3DMark05.
I also took measurements and made a breif analysis of the power draw consumed from this overclocked Opteron PC using Kill-a-Watt meter.
It has 4 hard drives, two Raptors in RAID 0, 2gigs (4x512) DDR, a TV Tuner, 5 fans, and a water pump!
in a Lian Li mid tower case.
Based on a brief quick test, and several follow-ups, I preclude that my AMD Opteron rig when over-clocked at 2.64GHz from 2.20GHz consumes:
≤ 200 Watts at Idle
≤ 255 Watts during Boot Up
and
≤ 365 Watts at maximum load when benchmarking using 3DMark06 (at 75% efficiency,
my PC is only requiring ≈ 275 watts of true power from my power supply)
Note: This is only the PC measured at outlet from the Power Supply; my LCD Monitor was not measured per these results.