Is PCI express 3.0 backwards compatible with the other revisions? I read on Wikipedia that this was going to be attempted, but I can't find anywhere this is confirmed.
closed as off topic by MDMarra, Ward, Chris S♦, Zoredache, Shane Madden♦ Nov 28 '11 at 1:43
Questions on Server Fault are expected to relate to server, networking, or related infrastructure administration within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here. If this question can be reworded to fit the rules in the help center, please edit the question.
Yes. The cards and bus (per card) will operate at the lowest common speed that both support.
Wikipedia: PCI Express mentions
PCIe 3.0 Base Spec §4.2.2 elaborates: