Gpu voltage is NVVDD
24/7 on air max 1.25v, bench only 1.35v
Most are running the PCI volts between 1-1.15v
You could even bench at 1.4v, one guy ran 1.55v on air!! But I wouldn't advise it.
I take it you have a custom bios on it??? Otherwise you won't have much luck past 1.25v
Isn't there a drop down box to switch cards??