A question about power consumption

[winterlude]

If you have, say, a 400 watt power supply, does that mean you are burning 400 watts all the time, whether or not your system is heavily loaded by, say, a game?

 

[Insidious]

No

400W is what it is capable of supplying if demanded.

It will only use what it needs

 

[airfoil]

Nope. 400 watts is the maximum load that PSU is rated at. Power consumption at idle will be significantly lower - figure at less than half that for a standard computer.

 

[UsandThem]

Originally posted by: Insidious
No

400W is what it is capable of supplying if demanded.

It will only use what it needs

:thumbsup:

There was a website someone listed here before, in which you list your setup and it tells you what the maximum power you will use if everything in your computer was being used all at once.

Found it!

 

[tallman45]

A better way to tell for sure is to get a Kill-A-Watt meter. It tells you exactly how much power any electrical device is drawing from the outlet

http://www.p3international.com/products/special/P4400/P4400-CE.html

or a Seasonic Power Angel

http://www.seasonicusa.com/products.php?lineId=8

I have a 3500+, 2-160gb SATA, 1gb ram, 9800Pro with an s12 380watt PSU and it draws only 105 watts at idle

 

[winterlude]

Thanks for the answers, guys

 

[YOyoYOhowsDAjello]

Just a note: all "400watt" powersupplies are not created equal. If you're shopping around for one, we can let you know what good ones are.

 

[Fullmetal Chocobo]

The SeaSonic Power Angels are nice. I found out my laser printer pulls as much power as my server does (4.6a on the 120v line). Rather surprising.
Tas.

 

[Lysawy]

400 is the celing and also look at the efficency of the psu

400w and 70% Load perhaps

Go for 500+ Brand name though

 

[YOyoYOhowsDAjello]

Originally posted by: Lysawy
400 is the celing and also look at the efficency of the psu

400w and 70% Load perhaps

Go for 500+ Brand name though

I think telling him to get a powersupply that will cost around $100 is a bit premature considering we don't know what his specs are 😉

(Or if he's even looking to buy one heh)

 

[0roo0roo]

look at the psu section of silentpcreview.com

 

[imported_rod]

Originally posted by: Lysawy
400 is the celing and also look at the efficency of the psu

400w and 70% Load perhaps

Go for 500+ Brand name though

Go for 500+ brand name?! We don't even know what his system specs are. A 380W Antec is overkill for most people.

Hell, you can safely run an FX-55 and two 6800Ultra's on a 480W Antec TruePower.

RoD

 

[ai42]

The only reason you need these monster PSUs is simply for overclocking. Overclocking inheriently is an exponentioal power curve in the amount of power required to sustation higher and higher clocks. For a rig non-overclocked the power usage is usually very very reasonable unless you are running either 10/15k rpm hard drives, or just insane amounts of everything (pci cards, hard drives, etc).

Yes Lysawy hit the nail on the head. 400W is only the maximmum amount of DC power the PSU can supply (FYI, if you are really anal you can check the rated wattages for the various voltages 3.3v, 5v, and 12v as you may not need as much 12v wattage as say 3.3v wattage for your application, 400W is simply the total of watts available for all voltages). And the power isn't free of course all PSUs draw more AC power (in wattage) than it supplies because the conversion is inheriently inefficent, due to heat generated by the process and fans drawing power to cool the PSU.

So in reality you may only be using 200W of DC power but the PSU draws 250W of AC power. And yes the PSU inheriently draws power proportional to the amount that is being used at the time. There is a little bit of power overhead to charge capaitors in the PSU etc but generally it is very proportional.

 

[aatf510]

My recommended waltage is 402w as of now..
I thought about upgrading to 2x 6800Ultra.. and bump!! 564w?!!!!!!!
that means I would need a new PSU?