So... up to 800MHz core (still stock volts, which is nice), and the improvement over my 885MHz core 460 is now 29.8%
Temps 87C and 64% fan stable, and fan is back down to 44% in less than a minute, so this is all looking (and sounding) good. On a par with my 4870 at load with 63% fan speed, but much more than that and I can see me getting annoyed with it, so that define the limits of my clocking rather than temps or the limits of the card.
Edit: oh, but I did notice that the heat of the air vented out the back of the card is insane! It really is like a mini-fan heater. I kind of dread the summer, but it seems to be coping ok at the moment...
Nice temps for a decent OC.
I am not going to attempt it for a while.
I want to make sure everything is ok before i tinker, but your description makes me want to as well

Aye, it does pump the heat out alright
