Power consumption

[Scoofy12]

OK heres a general DC sorta question for you farmers and home crunchers: about how much power will a computer that does nothing but DC use? more specifically, if i have a computer with, say, a 300 watt power supply, will it consume 300 watts all the time? Actually, since its output could be 300W, it would consume even more than that from the wall. But it seems to me that it would only provide as much as the mobo/proc draw, which ought to be less than 300W. anyone have experience here?

[ColinT]

This has been discussed to death. Your 300W PSU is not pulling 300W from the wall.

If you have a modern AMD XP1800 then you are pulling about 100W from the wall.

All this is dependent on the CPU type and the Number of drives and cards.

[FoBoT]

leaving one stripped down/dc cruncher on is about like leaving an incandecent light bulb on all the time, roughly (no monitor)

[ColinT]

Exactly!

[Chinasaur]

Colin,

Yeah..but it hasn't been discussed to death here has it? Probably on Ars.

I remember some good threads over there by Larry, poof and amelia discussing abstruse electrical theory to derive a consumption guide.

I think it would be a good item for a sticky or sidebar link if somebody can find a good technical thread or a chart. Along with processor benchmarking...

[Alpha_7]

Well I'm glad I'm not the only one to have debate on power consumption.... :) and I'm even gladder to find out that this other discussions findings concur with my own theories.

:) I'll have to tell my mate to have a look.. to prove once and for all I'm right... :D

[Scoofy12]

Originally posted by Chinasaur
Colin,

Yeah..but it hasn't been discussed to death here has it? Probably on Ars.

I remember some good threads over there by Larry, poof and amelia discussing abstruse electrical theory to derive a consumption guide.

I think it would be a good item for a sticky or sidebar link if somebody can find a good technical thread or a chart. Along with processor benchmarking...
No indeed it hasn't been discussed here. Now, as an electrical engineering student, I know enough abstruse electrical theory to guess that you probably wouldnt be pulling 300W all the time, but i also know enough to know that a) my knowledge of abstruse electrical theory is limited, and b) half the time the way people actually design things has little to no bearing on what they teach in university classes :)
thanks guys :)

[Daza]

Originally posted by FoBoT
leaving one stripped down/dc cruncher on is about like leaving an incandecent light bulb on all the time, roughly (no monitor)

Im going to quote you on that one to my parents :D

[dragongoddess]

So should we keep beating this dead horse or just bury it.:bang:

[FoBoT]

and actually, since a pc has more capacitance than a light bulb (totally resistive load), there is a good chance you would actually pull less current than a light bulb (but not that much, so just figure its like a light bulb)
ooops, i forgot about all the fans, if you add any fans, the inductive load probably counters the capacitance of the mobo, so it probably turns out to be nearly a 1 power factor circuit

so again, its about like a light bulb!! :D

[Paratima]

so again, its about like a light bulb!! Just not as bright?

[Alpha_7]

I hope your mobo doesn't glow as bright as a light bulb...
I suggest if your does, you go into bios and find the "Emergency Lamp" option and disable it. You'll find your power bill will drop dramatically :D :D :jester:

[Scoofy12]

wow... a unity power factor... but wouldnt a capacitive/inductive load acutally draw more current for the same power? that would mean that a unity power factor would be a good thing, right?
oh well... i guess we can lay this one to rest so we dont bug ppl too much then... hehe thx all :)

[Alpha_7]

Will have to borrow some Emtek Wattmeters from the lab... and use the 2 Wattmeter theory on it.. hmm or is that only for 3phase ? meh.. can't remember...