Today`s latest graphics cards come with support for PCI-Express 3.0, which promises twice the bandwidth, while still being compatible with older motherboards and graphics cards. In our article we analyze differences in PCIe performance on Intel`s Ivy Bridge with GeForce GTX 680 and Radeon HD 7970, using 20 games at five resolutions, each at all three PCIe generations and x4, x8 and x16 link width."
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips