Seasonic M12II 500W Power Supply Report
 

Whether you want to recognize it or not, power supplies are an integral part of your computer. And it's not just about wattage -- if you don't have a quality power supply that delivers, your latest quad core, pair of graphics card, and half a dozen of hard drives won't run stably. And then you would end up blaming that on the OS or whatever. On the other hand, most people with relative high end configurations probably won't even need 1200W power supplies anyway -- my Core 2 Extreme QX9650 and 8800GTS G92 (Plus all the relatively high end components) needed no more than a quality, efficient, high performance power supply that delivers what it's rated for. I used to run my computer off a Seasonic M12 500W.

http://aphnetworks.com/reports/seasonic_m12ii_500w