I pulled the 6925 card and it is a 2.3 version. My pci-e bios options are x1 x4 or auto, it was set to auto on install so I just left it, it seems to work okay there. Not sure what else to tell you, the mb is an Asus P8 Z77-V Pro. I'm using the 1.0.1.20 driver for 64 bit.