I have three ASUS 7970 and the voltage control on them as been hit and miss with previous versions of GPU tweak. This has always been the core not holding correct volts though. Say you set 1.4v in GPU tweak but it actually gets 1.39. The memory has always set correctly. This latest version sets 100% correct core values all the time but is way out with mem. infact its not setting memory volts at all above stock. I have tried several different drivers and different versions of windows Vista and 7. its the same on my Maximus series and Rampage series boards.