Which voltage monitor to believe?

[Endymion FRS]

Alright, so I got over my voltage lock barrier on my Gigabyte 7950 by flashing an older bios. However, changing voltage in Afterburner produces a different result in both HWiNFO64 and GPU-Z. I have Afterburner set to do 1100/1350 @1.2v, but HWiNFO64 still reports the card's stock 1.090v, while GPU-Z reports 1.175v. It seems wherever I put voltage on Afterburner, GPU-Z reports .025 less. I know the voltage change has to be working, because I just played Call of Pripyat for 20 minutes on those settings, whereas before I could only change core clock to 1000 and either not launch at all or hang at the main menu with a driver crash upon exiting. How do I know what my real voltage is?