Version 3.4a adds support for the 8800 Ultra and the 7900 GS AGP, and that means all sorts of finickity twiddling. You can change the BIOS default core and memory clocks, the voltages and fan settings, you can even change the vendor-specific sign-on message and some monitor-specific parameters.
If you think you've found a stable overclock for your card with software methods, why not hardwire it and dispense with the unnecessary overhead?
Source : Flash your Geforce BIOS
Get it here : NVIDIA BIOS Editor (NiBiTor) v3.4a Program Released :: MVKTech