I recently bought an MSI 7970 OC. It's a reference design card and it's supposed to be voltage unlocked (even says so on the box). I do have access to voltage control in Afterburner, but I have a suspicion that, for some reason, the voltage isn't changing, even if I tweak it in Afterburner. I'm thinking this for two reasons: 1) because my voltage in GPU-z is always significantly lower than what Afterburner says and 2) because increasing voltage in Afterburner doesn't help me improve my max overclock at all. I max out at 1150 on stock volts and increasing voltage up to 1.3v does nothing to help me improve on that. Have you guys ever came across a problem like this?