I see these 'PCIe 3.0' posts all of the time, we really need a sticky.
Q - How much of an 'improvement' in 'FPS' do you expect going from PCIe 2.x -> PCIe 3.0?
Q - How much of the PCIe 2.x x16 lanes is 'filled' by the GPU's out there?
Q - What needs the PCIe 3.0 added bandwidth -- the GPU(s) or Chipset?
IF you know and the answers to those (3) questions then do you think you'd ask this question? Sure after you answer I'll discuss this some more.