I have a Sapphire HD5850 Xtreme. The BIOS limit on the core clock is 900 MHz.
With Catalyst 11.6 I can easily increase the clock frequency beyond 900 MHz but in Catalyst 11.4 I'm not able to. (Catalyst 11.4 is quite a bit faster than Catalyst 11.6 for me).
To the person that can help me to clock my card significantly beyond 900 MHz while using Catalyst 11.4 without resorting to WINE/Windows/DOS/BIOS-flash I offer 1 BTC. I'll settle for a new limit of 1150 MHz or more.
Cant be donde whiout increasing voltage, voltages cant be increased beyond bios limit in Linux, AMDOverdriveCtrl only allow voltages changes in bios limit (so nothing, as the limit is the stock voltage).
You will need to do bios flashing, if you wish to, ive already uploaded instructions and modded bios for the 5850 xtreme in hardware.