I get that a lot, but its a misconception that computers now-a-days need boat loads of power, the most optimal range to run a power supply in is about 75-85% of full load, as thats when they typically have peak efficiency. People assume that with all these 600, 700 and 1000 watt power supplies running about that computers really do draw that much, but they really draw much less. For example, i have somthing called a Kill-A-Watt, which basically is a power meter, it plugs into the wall and the computer plugs into it. At full load (prime 95, playin any game (not really full load), 3d mark vantage, OCCT burn in test..and anything else i could run to suck as much power as i could) the system didnt draw more then 380 watts from the wall (was running 3d mark vantage and 2 threads of prime 95).
All that is not to say i skipped out on power supply quality, the corsair unit i got is a beast!, It has some of the tightest voltage regulation of many a power supply out there, and clean power is just as important as enough power! especially when overclocking