I recently got a 6800xt Merc 319 Core from XFX. Long story short, it over clocks very well, but it has presented me with a scenario that I've never seen before, outside of heat related issues. The best Graphics score I've been able to achieve is a 21271. That is with the following settings:
Min Frequency: 2500mhz
Max Frequency: 2600mhz
Voltage: 1000 Mv
VRam Speed: Max (2150mhz)
Fast Timings enabled
Smart Access Memory enabled
Power Limit Maxed
Thinking that maybe I could increase the score slightly by increasing the voltage, I put it up to 1100 Mv. Everything else stayed the same. My score dropped dramatically to 17962. This was repeated a few times. As soon as I put the Mv back down to 1000, my scores went back up into the 21200 range. At first I thought it was a heat related issue due to the increased voltage, but that wasn't it, as my temps didn't really change much (I usually sit around 70 degrees under load). Power consumption was roughly the same as well, and I'm hitting nowhere near my PSUs 850 watt rating.
What, besides heat could be slowing down the card when the voltage is increased?
Min Frequency: 2500mhz
Max Frequency: 2600mhz
Voltage: 1000 Mv
VRam Speed: Max (2150mhz)
Fast Timings enabled
Smart Access Memory enabled
Power Limit Maxed
Thinking that maybe I could increase the score slightly by increasing the voltage, I put it up to 1100 Mv. Everything else stayed the same. My score dropped dramatically to 17962. This was repeated a few times. As soon as I put the Mv back down to 1000, my scores went back up into the 21200 range. At first I thought it was a heat related issue due to the increased voltage, but that wasn't it, as my temps didn't really change much (I usually sit around 70 degrees under load). Power consumption was roughly the same as well, and I'm hitting nowhere near my PSUs 850 watt rating.
What, besides heat could be slowing down the card when the voltage is increased?