What model/SKU number is your card? Should be on the box with the barcodes and partially printed on a label on the PCB. I have a 11197-03-40G. Sapphire makes quite a few 7970s variants.
It's the same as yours, yeah. But I don't understand why my default is 1025mV and yours is 1170 mV. Similarly my default memory speed is 1425 MHz and yours isn't, is it? These differences mean I can't quite relate it to the other experiences people are having.
I'm guessing you're getting that voltage reading from GPUZ? It always gives a lower reading then afterburner, I think it might be because it reads the voltage of several components individually and other software reads them before they are split. Not sure on that though, but my GUPz reading are always lower then afterburner.
My default core voltage was 1175 mV or 1.175 V. I don't think I mentioned the default memory clockspeed, it was the same as yours, 1425. I keep it underclocked 150 MHz less then my core clock. Any lower and the card becomes unstable. So at 1150 it's safe to clock the memory down to 1000.
The dual BIOS comes in handy if you want to flash a modified bios with an overclock as the default setting.