Its been done. You have great chances flashing to a 5900 Ultra successfully.
I'd be satisfied with that..
but o/c and find out if it will work on yours.
The flash will probably lower memory timings (allowing higher clocks) and possibly raise the voltage on the card a bit as well.
Combined, if you can get the mem within 50mhz you should be ok to flash.
Its one of the reasons that this card remains such a great value. I flashed some 9800 non pros and found that trying different bios can be worth your time.
Some have different settings and allow your card to go higher.
I'd rather have slightly reduced timings with higher clocks myself.. just depends if the gains outweigh the losses in performance.
In my Radeons case, it did by far.
Just be prepared to lose the card and dont attempt without a backup of your current bios as well as a PCI video card so you dont have to flash it blind if it doesnt work when you think it might.
GL
____________________________
<b>RESIDENT FORUM WARRIOR
<font color=purple>I just neutered the cat.
Now he's a liberal.</font color=purple></b>