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?
To push it further, you need to give it more power; turn up the voltage. Only touch the voltage if you know what you're doing. If you're new to overclocking, I recommend you do some research, and experiment on a less-expensive card. Your fanspeed should be based on a curve ideally, not a set value. If your temps are below 90C, you're safe.. but I wouldn't recommend running at that temp 24/7. I would shoot for 75C max as a safe 24/7 temp.
Only the 2GB cards can be flashed to a 6970 BIOS. That's why most people don't buy the slightly cheaper 1GB version. I'm actually using a 6950 BIOS that was patched to unlock the unused shaders... I'm not sure if the 1GB 6950 can use that one, but it's worth a look.