I have been doing a lot of builds over in the Systems part of the forums and have really been wondering about PCIe 3.0 and PCIe 2.0 x4 CrossFire (or PCIe 2.0 x16/x4). A lot of users say that they want to (or in the future) CrossFire their GPUs. Many of the B75 and H77 (and AMD 970) boards have this combination of PCIe slots and claim that they are CrossFire ready (theoretically, they are) but how much of a real performance hit does the second card take on the x4 lane. I know that when you start getting into the Z77 boards most of them are x8/x8 but they are usually too expensive for budget builds. I have scoured the web for answers, benchmarks, etc. and can't find a solid solution. Some say very little hit, some say not recommended. So I am asking some of the fine experts, here at Tom's, what is the truth about this?