Originally Posted by cadaveca
You are right, if that board was built with PCIe 2.0 switching hardware, it cannot negotiate the full PCIe 3.0 x16 link, but it can still use PCIe 3.0 encoding. Some boards even switch down to PCIe 3.0 x8 in that instance, actually.
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 (and does not claim to support PCI Express 3.0 in any way), so I was NOT discussing that thing you mention.