[cadaveca]

Originally Posted by Naki

No, they do NOT switch to that!
However, the speed of PCI Express 2.0 16x is equal to PCI Express 3.0 8x, maybe that is what got you confused.

EDIT: Yeah, I heard about the so-called "Fake PCI Express 3.0" vs. "Real PCI Express 3.0" boards, but MY BOARD is ONLY PCi Express 2.0, so I was NOT discussing that thing you mention.

Yeah, that fiasco is caused by this "issue" of what supports what. Some board makers "force" PCIe 2.0 in BIOS, but at the same time, most P67/Z68 PCIe x16/x4 boards work perfectly fine.

If the BIOS doesn't force PCIe 2.0 when IVB is installed, many different scenarios are possible, and it's all dependant on what switches are used, what the BIOS does, etc.

Take a look at all the OEM claims on the issue, and you'll find the answers. I had to ask them all directly, and many did not like me asking, and this caused some issues. I won't forget that whole episode, let me tell you.