Power supply question about 7900gto

escalade87

Distinguished
Jun 18, 2009
4
0
18,510
Hi, on my psu it says: +12V1 = 18A , +12V2 = 18A, and under it it says 385W MAX. Its a 585W power supply from safe power. Does it mean that it can handle all cards below 18A+18A= 36A? Is it enough to run a 7900gto, and if not what cards can it handle?
 

escalade87

Distinguished
Jun 18, 2009
4
0
18,510
hmm the card requires 22A on the +12v but i have two 12V with 18A, is it safe to say that I have 36A or do I need a power supply with a 22A on a single +12V
 
Whilst my maths skills are crap I do know that you can't just add the rails, it is not 18A + 18A = 36A, it's probably closer to 28A - 29A. It' s more a question of, how old is that PSU?, and can it actually supply what the sticker on the side states it that it can?
 
Do n't bet on older tech not drawing much power, the Prescott Pentiums were notorious power hogs and some of the earlier X2 Athlons could chew through 120W with ease.
Mousemonkey is right about the 12v rails, according to the specs you have given the maximum combined output of 385W equates to 32 amps (amps=Watts/volts and 385/12 is 30.083... amps).
According to this site the card draws about 90W:

http://forums.atomicmpc.com.au/index.php?showtopic=264

Even assuming a heavy CPU draw you'll be just fine.
As long as the label is telling the truth.
 

:eek: I could not remember the formula so I guessed at that without using a calculator, just a skinful of beer!