Since the thread was bumped, I realise there's a lot I haven't updated.
The overclock to 3500 MHz at below stock voltage was stable and is what I'm running it at currently.
I did push a little more to see how far I can go, and stopped at 4 GHz at 1.4V. Maybe I could have gone further but I had seen enough as power and heat was building up rapidly at this stage.
I had a non-activated Win7 install put on for initial testing, with the intent of switching to Ubuntu for long term running. That hit a brick wall as for some reason it refuses to see SATA hard disks. Windows has no problem. Even trying to revert to a PATA hard disk didn't work. It saw it, but the performance was horrific. I suspect out of the box Ubuntu doesn't like the AMD chipset and I don't fancy spending more time finding out how to fix it. Got XP installing now and sacrificing 64-bit mode... does that even support 6 cores?
_________________Canon DSLRs: 7D2, 7D1, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 10-18, 15-85
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 50/1.4A, 150 macro, 120-300 f/2.8 OS
Compacts: Sony HX9V, Fuji X100.