Power consumption of my Windows Desktop

I ran into a rather interesting discovery regarding power consumption of my PC while in sleep mode.

Using a Kill-A-Watt I measured how much power my computer uses.

While under normal operation, I use around 120-170 Watts. This is reasonable for my hardware - Core 2 Duo 7200, GeForce 6800GT, 22 inch ViewSonic flat panel.

Then I tested the watt usage while the machine was in a "Sleep" state. The result was a surprisingly low 13 watts.

I noticed that I could not wake my computer up using my USB keyboard, only the power button. So in Control Panel -> System -> Hardware -> Device Manager -> Keyboards -> Power Management I checked "Allow this device to bring the computer out of standby". I then re-ran the test with the Kill-A-Watt.

With this option enabled my consumption during sleep mode went up to 66 watts! That's a 500% increase!

I leave my PC on 24x7x365. Looking at my last bill I pay .16 cents for a kilowatt. Having this option turned on will cost me an extra $75/ year. No thanks, I'll just push the power button to wake up from now on.

If anyone else has a way to measure energy consumption - post your results.


Colin Gebhart said...

Good catch. I don't think I have ever read about a difference in sleep power usage when certain options such as device wake are enabled. I've been looking for an excuse to get a kill-a-watt, maybe this is it.

I plan on getting my MythTV up and running again. That's going to be probably a 150 watt 24-7-365 draw. Yikes! Maybe the Tivo monthly fee and lower power draw would be cheaper in the end.

And man, your elect rate is pretty stiff. I pay 13 cents/kwh not counting the customer and meter flat fee. I can get supposedly 100% wind generated for 15 cents/kwh through GEXA Energy. It looks like similar rates are available in the Woodlands if you are in a deregulated service area.

phillip said...
This comment has been removed by the author.
phillip said...

Thanks for the tip, Ern. It should definitely help. One thing I wanted to mention was that sometimes I move my mouse to wake up the computer and when making the changes to the keyboard settings, I found that my mouse settings were identical. I also unchecked the settings for the mouse, but was wondering if you had done the same and if so, what was the kill-a-watt difference. Thanks!!

Frank said...

Compare that to a laptop with your Kill-a-watt and I'm sure you'd see a huge difference... as long as you unplug the cord when you're done charging.