In the thread titled "X800 GTO2 Thread, post your mods and clocks here"
http://forums.overclockers.co.uk/showthread.php?t=17478555
there are people who have done it... Examples...
Bito
Just flashed mine with the Crucial X850XT bios !!
This bios is for the VGA/DVI X850 cards, same layout as the GTO2
Using ATi Tool to speed up the fan, it works great as a fully fledged X850XT!!
Will try for more later, when i get my w/cooling back up
I already know the memory goes beyond the PE speeds
Wr8ith
Mine turned up yesterday., along with a new mobo. (Previously had an HIS 9800Pro 128mb)
After re-installing Windows, a bit of tweaking with ATI Tray Tool / ATI Tool, this is the highest i've had it:
Core: 400mhz > 550Mhz (Stable)
Memory: 490mhz > 580Mhz (Stable)
I've dropped it back to 520 Core / 540 Mem for now until I fit the arctic cooler (hopefully reduce the fan noise!), then I'll do more testing
Also successfully modded it to 16 Pipelines, as per techpowerup instructions.
Quite impressed so far, since I just wanted a cheap card for the time being so I could go PCI Express.