Big Navi Voltage Hacks?

[hihihi8]

Hi all. I've been playing around with my reference 6900 XT.

I've got MPT set to 360W GPU Power (415W under load), and managed to get #10 on fire strike ultra the other day. The thing maxes out at only ~52c under furmark. But I can't the push core clock any higher (max 2820mhz) at the current voltage of 1175mV

I was wondering if there is any way to increase the voltage limit on these cards. If i try to increase it in MPT, it locks itself to 500mhz. Is this something a bios mod can get around?

Thanks