What kind of power does a desktop use left on?

[CrAz3D]

My friend is obnoxious about the power bill.  His dad pays it and its up there, but my friend leaves lights on all the time ::)

Any how, I'm wondering if I should hibernate, sleep it, or just leave it on.

[Sidoh]

Well, hibernating saves everything you're doing to a session and completely shuts off the machine, so unless you need your computer doing something while you're AFK, hibernating it sounds like the best option.

This is a pretty liberal calculation, but it ignores the power that your monitor, speakers, etc take up.  This kind of gives you the idea, though:

Assuming you're using a 350 watt power supply and it's operating at 100% capacity for a full day and electricity is $0.10/kWh, it would cost you...

350 W * (1 kW / 1000 W) * 24h * ($0.10 / 1 kWh) = $0.84/day.

I think that's right, anyway...

[igimo1]

If you leave it on all the time, it runs up to maybe $5 at the end of the month. If you don't... probably less than $3

[Skywing]

You should measure it yourself as your actual usage is going to depend on hardware and whether you are taking advantage of power consumption management features (and if so, what sort of load your system is under).  Prices are obviously going to vary significantly based on localation and time of year, so saying "$3-$5 per month" is fairly meaningless.

I would be surprised if your system uses 350W while idle, though.  My dual-core Xeon tower server + external HDs, switch, access point, and cable modem use something around 100W combined.  Current laptop uses max draw (130W) while charging, but operational usage is typically a fair bit lower.  I think the highest I've seen it go while not charging was 80-90W while on wall power and pegging the video card and both cores.  While not maxing out video, it's typically 20-30w depending on load and things like screen brightness and which radios are enabled.

[Sidoh]

Yep, like I said, it was a liberal calculation. :P

[iago]

Hmm, my answer was going to be "AC power"

[Sidoh]

Hmm, my answer was going to be "AC power"

Haha!

[Ergot]

Hmm, my answer was going to be "AC power"

So... You don't have a power supply?