Are pcie 3.0 graphics cards compatible with pcie 2.0 ports?
I presume that you mean to ask whether a PCIe 3.0 card can be
used in a PCIe 2.0 slot on your motherboard. The answer to that
question is yes. PCIe standards are all backward-compatible, so do
not sweat that. For best performance, however, you would prefer to
put a PCIe 3.0 card in the same type of slot.