For overclocking with software such as Rivatuner in Windows, see this thread:
Guide to Overclocking Video Cards
For BIOS editing and flashing help, see one of the two guides below:
ATI/AMD: Guide to ATI BIOS modding and flashing
NVIDIA: GUIDE: Nvidia BIOS Modification v1.0
Guide to Overclocking Video Cards
For BIOS editing and flashing help, see one of the two guides below:
ATI/AMD: Guide to ATI BIOS modding and flashing
NVIDIA: GUIDE: Nvidia BIOS Modification v1.0