If anyone knows how to adjust voltage through 11.04 or Windows 7 I'm all ears.
ATI Tray Tools.
Download and install Rivatuner. Since it's an old utility, it cannot detect your cards. Download and run RBE. If it detects the installed Rivatuner, it will prompt you to authorize adding your cards device IDs to Rivatuner's list of supported devices.
Use Afterburner to set the core and mem clocks, disable auto loading of AB every boot. Close AB. Open Rivatuner, detect clocks and enable "Apply overclocking on Windows startup".
Your cards will now have the customized settings even after reboots.
I use this method on my 6870s with 960/134 clocks.
AB was based on Rivatuner but I don't why my mem clocks revert back to default after reboot even if I configured it to apply the modified clocks on startup. My cards also locks up my rig if I set mem between 319-415. Stable clocks are 133-318, 416-1100.
Thanks for the info, but I've no problems with changing voltage and mem with Win. I need linux on usb flash stick. So, thats why I need to know how to change voltage and mem in BIOS without getting bsod. Or theres any other alternatives for Linux, some apps for changing voltage at least which will work for 6870?