Hi John, so you're saying that even though GPU-Z shows the bus interface at x16, it only runs at PCI-E 1.1 x16 but not PCI-E 2.0 x16? I have some screenshots and hopefully they help. Does it only affect to Nvidia card but not ATI?

My board is a Maximus Formula X38 that flash to a Rampage Formula. I have the GTX 275, GTX 285, GTX 295 as shown below: