I would think that 500 watts is a minimum these days.
Well that unfortunately is a wide spread rumor which is not true. When using just one graphics card you'll rarely need more than 400-450W (that excludes those two chips on one PCB cards because they of course have a higher power consumption too just as the same disadvantages of such dual combos). The only thing you have to take care of is to actually use a quality power supply and not like let's say one from LC Power who really produce quite a lot of poor supplies. I for example have a Phenom 9850 with a HD4870 running with "just" a Seasonic S12-430 (-> 430 watts) and it's all fine. If you want to know some numbers of how much an insane high-end and overclocked system needs just look here:
http://www.computerbase.de/artikel/hardw...istungsaufnahmeWhen talking about recommendations for power supplies I'd go for either be quiet's E5 series, Seasonic's S12 series or Enermax's 82+ series. They all are of very good quality, have a high efficency and run very silent...
Enjoy your meal
Toast
