Use "Unofficial Overclocking Mode" in MSI Afterburner (enabled via the config file).
I posted a thread over at Guru3D and Unwinder responded:
http://forums.guru3d.com/showthread....98#post4216598 . He says the AB is working as intended and the sensors are just off. It still doesn't explain why adding Vcore adds little to no overclocking headroom, maybe it's a temp thing or I just have a bum chip :shrug:. Anyway, doesn't seem like there's an issue. It would be nice if someone wanted to do the vGPU read mod and confirm with a multimeter.