Wish I could post this in the section it belongs in since I'm not really a newbie but oh well...

I just got a sapphire 6950 1gb version, and have been trying to overclock it (for bitcoin mining at the moment). I've tried using different programs (CCC, afterburner, trixx) to overclock, and can get the core up to 900, but once I go much past this the card immediately throttles down. I've tried increasing the power control in CCC, but it doesn't seem to do anything. Is there any way around this?? Thanks in advance