Power supply question

[Derrmerth2]

<p>I've never really had to get in the technical guts of power supplies and thier real power ratings but it seems the time has come. I have right now a OCZ GameXstream 1010w PSU and tried to hookup a BFG GTX 260 core 216 OCX to it and had problems. I've come to the conclusion that my power supply being a year old didn't have the muslce to power this thing. I've done a ton of research in to it and I think I have my answers but I'm gonna ask here. I've spit my share of advice out, time to be on the recieving end. <img src="http://forums.station.sony.com/eq2/images/smilies/97ada74b88049a6d50a6ed40898a03d7.gif" border="0" alt="SMILEY" width="15" height="15" /></p><p>I have a fair grasp of most things PSU related, but the true power output and math of combining rails has never been a question until now.</p><p>First up: I know the basic math formulas for power dealing with watts, amps, and volts. I also know that if you use two 12V lines with 20A each, you don't get 40A in the end. The card I was using asks for at least 38 it seems. So my first question is if there is an easy way to figure out what the real amps coming off a line are. Is there a combination of power formulas or if my numbers work out, is it as easy as multiplying the efficiency of a PSU times its labled amp output. Example 87% eff rating, 20A line claim, you really get 17.4. </p><p>Second: My PSU claims 20A per 12V line, this may be answered by an answer to the first one, but Im guessing the amps from the two 12Vs is not enough. </p><p>Might be more depending on what I learn <img src="/eq2/images/smilies/3b63d1616c5dfcf29f8a7a031aaa7cad.gif" border="0" alt="SMILEY" /></p>

[Despak]

<p>I have run 260's and 4870's (in crossfire) off OCZ 850W PSU's with no problem.</p><p> The 1010W would be more than adequate to run a triple sli setup IMO.  I would hazard a guess (without knowing what you mean by problems) that you have either a faulty card or PSU.</p>

[TSR-DanielH]

I would think that the PSU you described would be fine, and I'm kind of suprised that it's giving you trouble.  Sadly, calculating power supply amperes per line is a little outside the scope of the support we offer.  I would help, but I intentionally forgot most of my electrical engineering classes the second I walked out of the classroom(though I still get glimpses of the homework in my nightmares sometimes).Hopefully someone who didn't block out their memory of that class will be able to help.<img src="/eq2/images/smilies/3b63d1616c5dfcf29f8a7a031aaa7cad.gif" border="0" alt="SMILEY" width="15" height="15" />