That's nothing. It's not like he is running both his CPU and GPU at full load. Regardless, I ran my i7 3.9ghz (99% load in Seti@Home) + HD6950 unlocked into a 6970 (99% load in MilkyWay@Home) at the same time on a 520W since February (that is until I started mining).
i7 3.9ghz by itself consumes 250-275W. Quality power supplies can run 24/7 100% load at their rated watttage. This isn't Rosewill or Aspire/Apevia crap.
but but but the box on my 6950 says it needs a 600W PSU just for it!!!!