Old thread bump, I know, but it's exactly the steps I've taken so far so need to go through them all again.
What I'm wondering is how the other posters in this thread have managed to adjust their Core Voltage on this card (6850). In Afterburner I only have the option to adjust core and mem clock, and fan of course. I am also able to adjust these values outside of the manufacturer "OC" specs, so currently I'm working my way down at 957, keeping my fingers crossed that I don't have another gpu reset. From what I understand if I were able to up the voltage I may be able to run these slightly higher clock speeds with more stability. I've been through the EULA in the config file and the switches in afterburner settings so AFAIK I've unlocked the program to its full potential, just still unable to adjust voltage though.
Specifically my card is a XFX Black Editition Radeon HD 6850. Does XFX not allow core voltage mods or am I not unlocking the afterburner properly? Thanks.
Try Trixx, it lets you adjust voltage. I used MSI fterburner for a while but Trixx gives you more control over your card.