AMD recommends 500W but most in the forums here would recommend 600W or more, esp if you're overclocking your CPU and have a lot of drives like I do (see my rig info). If you're looking into a new psu then check out johnnyguru.com for some good recommendations.
Actually many have been able to reach 1200+ on air, so my 1150 is perhaps average or even less than average. One thing I've discovered is that if you set TRIXX or AB to 1.3v for VDDC it only scales that high, meaning that if you monitor voltages via GPU-Z you will see that rarely does vCore reach the peak, even if you're running something like FurMark. I believe you could set VDDC to 1.315 and still stay within safe margins, granted that temps stay within check. Just make sure that when you go over 1.2v you don't set the software to force constant voltage as that will surely degrade or kill your GPU over time.
While I wasn't too lucky on the core, I must say that the VRAM on my card is superb. If I could dissipate the heat I think it'd reach 1850 or perhaps 1900. But overclocking VRAM doesn't yield nearly the performance as the GPU so I clocked it down to control heat and leave more "room" for cooling the core (it makes a difference).
Several posts back I mentioned about lapping the cooler (or was that another thread?). It's a rather awkward process as the screw retainers (four of them, one in each corner) are molded as part of the heatsink, so you can't lap it using a block to maintain uniformity. Nonetheless, it can still be done and it shaved a few degrees C off my temp and allowed me to reach 1200 whereas before it took too much vCore and heat quickly set in. To lap the heatsink I cleaned the old TIM off with an old handkerchief and some rubbing alc, using an old toothbrush to clean around the die. Then I used ArtiClean to clean things up and applied about a BB-sized amount of PK-1 paste to the core and put it all back together, alternating screw positions to seat the cooler correctly to the PCB.
Edited by NLight95 - 3/12/13 at 7:57pm