On Mon, Dec 28, 2009 at 11:09:48PM -0000, Ted Harding wrote:
On 28-Dec-09 20:57:14, Chris G wrote:
While this isn't particularly Linux related it is PC related and I'd guess some people here may be knowledgeable in this area.
I'm trying to cut down my PCs' power consumption, one way has been to offload 'server' functions from my desktop machine to a much lower power server machine. That's now done and I'm looking at other ways to reduce power consumption.
I've been looking at the power consumption of my desktop machine and noticed that when in standby it consumes about 20 watts. So I checked how much it consumed when powered down completely (but still conencted) and it *still* consumed 20 watts. I.e. the power supply and motherboard even when completely idle take 20 watts. I suspect that this is mostly power supply losses.
I have met this sort of thing before (though a long time ago, and I don't remember all the details). It was something to do with the fact that switching on was done via "intelligence" on the motherboard, i.e. instead of having the power button closing the power circuit by mechanically closing a switch, pressing the power button simply makes a connection between two pins on the motherboard, which then sends a signal to the PSU which then turns itself on.
As a result, the motherboard (and associated PSU circuitry) are permanently taking power in order to remain in a states of "alertness" while waiting, tongues hanging out, for their Lord and Master to touch them with the Finger That Giveth Life.
If you want to suppress this, then of course switch off at the mains! Hoping this helps (it may be barking up the wrong tree, in your case).
Yes, I know that, however I think the power used at idle is mostly the 'overhead' in the power supply rather than the 'keeping awake' power of the motherboard. This is what I was trying to explain.
The fact that when the motherboard actually is 'running' (well, sort of) in standby mode the power consumed is near enough identical to when it's 'off' suggests to me that most of that 20 watts is losses before the motherboard. Hence I believe a different (but how to choose it) power supply will keep the motherboard in standby mode but won't use so much power.