Power Consumption Data

All numbers gathered using a Kill-A-Watt meter.

System Specs:
Windows 7 Ultimate RTM 64BitAMD Phenom II 3.0ghz overclocked @ 3.3ghz
Nvidia 8800GT
8GB DDR2
DVD Drive (Idle in all tests)
2x 500GB 7200 RPM SATA Hard Drives
2x 300GB 7200 RPM SATA Hard Drives
28" Hannspree LCD @ 1920x1080
22" Acer LCD @ 1680x1050
Logitech G5 Mouse
Logitech G15 Keyboard
X-Keys USB (20 Keys)
Plantronics USB Headset
Logitech 5.1 Surround Speakers

Configuration of WoW:
I am running wow with Innerspace configured by ISBoxer. I run 1 full screen instance @ 1920x1080 and 4 thumbnails running PIP which also render @ 1920x1080. I do run "DynamicPerformance" to minimize the impact of the non-focused windows.

Main audio comes from the Logitech Speakers while Ventrilo is channeled to the USB headset.

Methodology
Cost per KW/H was extrapolated from my last months power bill. Power costs me $0.08/KWh.

I gathered a baseline expense to run the system as listed above with zero load. The system is set to "high performance" in power management and nothing ever gets shut down, spun down, allowed to go to sleep or otherwise inconvenience me, the user. After 2 hours of running the system costs $0.03 / hour Idle.

I gathered the load numbers by traveling around Dalaran on a Friday night on a high pop server. I did this first as a 5 box team with all 5 running laps together, and then close 5 clients and ran just the one client for the same duration. Each test was approximately 30 minutes, I'd do a longer test but I was very bored after an hour.

Results
5 Box Result - $0.044 / hour
1 Box Result - $0.038 / hour
Idle Box Result - $0.03 / hour

Good info thx.

The odd thing is that I'll be a lot of older systems are just as expensive. I think the old 90nm P-4's were 140watt CPUs. RAM and Hard drives have decreased in voltage as well, but I haven't really noticed what their total watts consumed is/was. Modern power supplies are often 80% efficient, and sometimes 85%. 65% efficiency used to be pretty standard. That made some old 300 PSU,s actually burn through 583 watts where a new 500 watt PSU that's 85% efficient will take 588 watts to power it. I hazard to think about LCD vs CRT wattage.

I think the important thing to realize is that the bulk of the electicity cost comes from when we aren't useing the system. Even if we just let it sit idle, that's $0.03 / per hour which is $0.72 / day, which is $21.60 a month or $262.80 a year. For those of us with multiple PC's, this can really add up.

I'm no where near that knowledgable when it comes to power usage, but if I'm reading this right you are saying that a single old computer may well burn more power than my quad core monster that can run 5 copies of wow?

It could be pretty close. But the graphics cards on older PC's didn't take near the juice that they do now. The whole reason 1000watt+ PSU's came out was when people were looking to put the old P4's and a couple of 8800Ultra's in the same box (yes I know the 8800's came after the P4 era was over). That's about like just leaving a hair drying running full time - probably puts out just as much heat too.

But on the other hand, PIII's and the K7/K8 althons were pretty efficient. So if you're trying to compare an older K8 with something like a Ati 1600 then that would be pretty efficient. Multiple GPU's didn't used to be more than a very small niche market too.

I'd be very interested in seeing the stats on a few lower end machines. The debate of which is more cost effective and all that.