How do people get their 6950s to go so fast?  I've got a PowerColor 1Gb 6950, 800Mhz stock running at 850, 1250Mhz RAM and 0% power control setting.  If I push it to 875 the PC locks up and reboots.

Temp is 65C and fan speed 56%.  Is it safe to push the power control setting up to 20?

I tried to unlock the shaders by ripping the BIOS, changing the 6950->6970 setting and uploading back again.  No dice.  Card requires the BIOS switch to be flicked before the PC will boot.

How much difference to power consumption does reducing the memory speed through reflashing the BIOS make?