I rarely turn off my PC, but I did yesterday and I noticed that the power meter showed "01" Watts. If the computer is turned off shouldn't it be 0 watts? The power meter is a P3 Kill-A-Watt P4400.

Also, when the PC is suspended, it shows "03" Watt. Is that 3 watts or 0.3?

I think the PSU will still draw a little if it's just soft-off as opposed to the cable being pulled out.

I can understand 3 or 0.3 watts in S3 suspend mode, but "off" should be OFF

If your PC is "off" because you shut it down, and it is still connected to the mains then there is still Voltage available to the motherboard (often this can be seen in the tiny lights indicating the supply is present). This allows the kind of power control circuitry used by PCs, where the PSU is "jump started" into full operation when it detects a current caused by depressing the front panel power switch. The only way to truly kill consumption is to flick the switch on the back of the PSU, or pull the plug.

there are a lot of electronics that use juice when "off".

My iMac might use more power when turned off then when it is just put to sleep! The meter actually cycles between 0W and 5W in both instances, but the 5W state seems to last longer when it is off. I won't be turning it off now.

iMac is probably charging its battery.

ok. So is "01" = 1 watt or 0.1?

For "03" suspend mode, I'd always assumed that the power meter has a funky decimal display for 0.3 watts, 3W seems too much for just keeping the memory alive.

"01" = 1

Also, there is no battery to charge in the iMac.

Well, it's not just keeping the memory alive. It's powering all of the power losses of the PSU, voltage regulators on the motherboard and so on. 3W in S3 is pretty damned good if you're using a standard ATX PSU.

Welcome to vampire load. If you really want something off, you have to flip the switch at the power switch or unplug it.

You're lucky - many crappy power supplies continue to pull 5+W when "off".

Anything you have plugged to the wall draws something even if they're turned 'off'.

Pretty much all devices draw a small amount of current when off. If you look at motherboard reviews over here you`ll see that most systems draw 1-2 watts when off, 3-4 when in standby.

Using a power bar is the easiest way to reduce this waste. Even so, the power bar will draw a tiny amount of power unless you pull the plug off.

That depends. A cheap one will be just some wires, sockets and switches, and so will draw no power at all by itself. One with neon lights will draw a tiny amount for those, and one with a filter will draw some imaginary power (but no real power).

PCs are "soft off" by default so that things like wake-on-LAN will work. But every single ATX PSU that I have ever seen has a proper hard switch on the back. Turn that off and you will have zero power consumption.

I've been trying to do this, but WinXP will BSD out of hibernate. Not sure if this is due to my PSU, mobo, whatever -- but it's a consistent result. There must be some kind of weird power spike.

My setup is:

Smart strip with a UPS plugged into the master outlet. I plug/unplug my Wii, Xbox, laptop into the UPS when needed. Because all of these things draw vampire power, I wanted to shut the UPS down completely -- fine for the consoles, but doesn't work at all for the PC. (Plus, whenever I turn on the UPS for the consoles, the PC gets that sudden jolt of power and boots without my say-so).

Any thoughts on this issue?

I have had a few motherboards that had a BIOS option to automatically turn themselves back on after a power cut.