hd 3850 - how much wattage/amperage is needed?

[thefuzmixman]

I have run into performance problems while gaming with my video card and I think the culprit is my power supply. I experience extremely low framerate while playing Crysis even at all low settings which this card shoudl be able to handle easily. It always drops to about 20 something fps during heavy fight sequences regardless of how high it is elsewhere. I have tried the various Crysis tweaks and while it helps my top fps, it does not help my low fps.

The specs on my PSU - 580watts at 75% efficiency with one single 12v rail rated at 11A.

I fear this is far too low to power my system but i do not know for sure. I do not know how many amps or how many watts my video card needs. Minimum specs just to see if i am really seeing a performance issue based on my psu would greatly appreciated.

Note, my system if needed-

e2180 intel dual-core (oc'd to 2.8) w/ Asus v60 cpu fan
Zotac nforce 610i chipset motherboard
Asus radeon hd 3850 512mb video card (oc'd to 700/1000)
2.5 gigs of ddr2 ram @ 667mhz
Sunbeam hush 580watt PSU (+3.3V@8A,+5V@15A,+12V@11A,-12V@0.5A,+5VSB@2.0A )

 

[Onus]

My first thought when I saw "+12V@11A" was "Well no wonder!" That would be nowhere near enough. The written specs at Newegg concurred, but the pic at http://www.newegg.com/Product/ShowImage.aspx?CurImage=17-709-012-14.jpg&Image=17-709-012-11.jpg%2c17-709-012-12.jpg%2c17-709-012-13.jpg%2c17-709-012-15.jpg%2c17-709-012-14.jpg%2c17-709-012-06.jpg%2c17-709-012-07.jpg%2c17-709-012-08.jpg%2c17-709-012-16.jpg&S7ImageFlag=0&WaterMark=1&Item=N82E16817709012&Depa=1&Description=Sunbeam+Hush+PSU-HUSH580-US+580W+Power+Supply of the label shows it has 25A on that rail, which should be enough.
So, which is it? The latter makes a lot more sense, but I don't think I'd trust this model.
I've got an Asus EAH3850 myself, and it runs fine on my 500W PSU, although I don't play Crysis. That game is supposed to be a GPU eater, but running on low should be no problem. Your card may be defective, but it could well be that PSU. If you get a new one, I would suggest selecting a model from Tier-3 or better from the list at http://www.tomswiki.com/page/Tiered+PSU+Listings?t=anon. It's a dated list, but still not a bad place to start. A PSU is not the place to be cheap, as your entire system depends on it, and can be killed if a bad one croaks violently. FSP makes some capable models that are fairly inexpensive, but you should still expect to spend at least $50-$60.