I assume you have a 7900 GS (you write 9700 GS which exists as well).
If you want to do the GTX-Mod therefore flashing the card to "look" like a GTX (it's recognized as a GTX and can overclock higher but DOES NOT perform like a GTX, 'cause the GTX has got 24 pixel pipelines compared to the 20 pps of the GS).
If you want to go the whole way flash the 790GTXUO.ROM
If you want to just enable overclocking flash 790GSUOV.ROM OR 791GSUNV.ROM (according to your revision! 790 is revision 0 and 791 is revision 1! If you flash the wrong revision, your card can't display anything anymore so you need to flash it blindly in order to repair it (if it's repairable at all)!!!)
I take no responsiblity if anything goes wrong! You do everything at your own risk!!
You can look up your GPU's revision in BIOS.- Revision 0 (rev.0): with bios 05.71.22.16.13.
- Revision 1 (rev.1): with bios 05.71.22.28.01.
The long number 05.71. ... is the thing you want to look for ;-)
You can look up what the abbreviated names stand for here: http://web.archive.org/web/200709121...jlgm/peng.html
It's the original site (or at least a backup of it!). The 790GSUOV for example means: it's a BIOS for 7900Gs Revision 0, the memory timings have been optimized, overclocking is enabled and the card is voltmodded (higher overclocks run stable, but more power is consumed => more heat and less battery)