[recoilfx]

Quality PSU is always a must, I didn't advocate for crappy PSU.

However, having anything >500w quality PSU for one 580gtx is excessive.

Alright, time for empirical evidence.
My system is currently this:
4ghz i5 2500k (lowered the clock last night because I wanted turned some fans off for quieter operation).
570 gtx
1 90GB SSD
8GB (2x4gb)
1 120GB SSD
1 2TB HD
GA-Z68MX MB
3 fans running (in quiet mode).

Using Killwatt, I get this:
Idle is <80 watts.
Black death track on CloD never tops 280 watts

Remember this is wall draw, not output. It's efficiency is at around 90% at that wall draw, so the actual PSU load (using my sloppy math) is 252 watts. That means during gaming, the PSU is only at ~50% load. Average load would be even lower!

I think my system is running fine with a 40% margin buffer. If a PSU degrades that much within its life time, then it s a crappy PSU people shouldn't have bought in the first place.

What people should really doing is buying PSU that will give them the best efficiency given their components, and right now, for one GPU system, no more than 500watts (for a quality PSU).