HD7970 overclock limit.

Anyone know a way around the 1125/1575 barrier? In both Overdrive and MSI Afterburner that's as far as the slider will let me go, and given that I can clock to those speeds with no change in voltage I know the card can go further than that. What I'm seeing of reviews (launch day ones at that) it can overclock well beyond this as well.

I'v read a couple of solutions ranging from flashing a new BIOS to the 7970 (not the Ghz Bios, something else) to altering the coding of Afterburner.
Just wondering if anyone else knows a way around it, preferably that doesn't involve messing with the back end of anything.

Also, Bonus question.
I'v been using 3D Mark 11 Basic to test the overclock to see if its stable, with the added bonus of it pumping out a score at the end telling me how much better I am for overclocking. I have found that if I increase my memory clock beyond 1450Mhz, my 3D Mark11 score drops, which doesn't make sense to me. I even bumped up the memory voltage to see if that was the issue, but no dice unfortunately.
So, do I trust 3D Mark11 to be right on this aspect, or just push the biggest memory overclock I can because in actual games there will be a performance benefit?
Suppose I could just run a game benchmark to figure this out :p.

Thanks.