On a Titan that you once knew, running at the 1.28 volts at 1.267 ghz a 7811 unit consistently got a TPF of 0:54 which calculates to 219K PPD. I didn't try any higher yet. I haven't tried the LLC hack from Zawarudo or whatever his name is.I'd love to see what a Titan would do w/ watercooling and similar voltage. Assuming it could clock to the same as these GTX780s, the extra shaders should give a consider increase. A 15% decrease in TPF is a 50K + increase in PPD.
Without knowing the acceptable limits of the chip's accepting voltage, I can't say, but on the Titan thread there were some concerns about the VRMs, but these deaths were attributed to poor cooling and/or extreme voltage and hard mods.I've been using the Zawarudo LLC hack and it has worked great. The only issue is that I need to start it every time I reboot. The card has been rock solid stable @ 1.325V 1372/3200MHz for a week w/o a single errored out WU. Time to figure out what kind of impact such a 'high' voltage has on the card in the long term.