I am getting like 300+ kh scrypt hash rate no matter what I do, this really sucks!
The speeds seems to be exactly same with 1333mhz, and 1600mhz RAM. Please PM me if you can find any settings that perform better. Hope this helps.
What software are you attempting to use to change the memory voltage? MSI Afterburner works for me with a Sapphire 7970 Dual-X. There will be a drop-down type arrow right next to the core voltage control that you can click on and it will reveal the memory voltage control.
As for your hash rate, try these settings in cgminer:
That gets me ~690Kh/s @1019mhz core and 1496mhz memory (core voltage set to 1100mV, mem voltage 1500mV).