What about a drop to 4x which would be the case if I were on Z97 with dual GPU and PCIe SSD. Would that be noticeable? Would that performance be worse than Dual GPU at 8x and a Sata3 SSD?
I think you're getting hung up on the 4x vs 8x. To summarize what other people in this thread have already said:
- For a single card, performance will be identical whether it's running at PCIe 3.0 x16, x8, or x4. So don't worry about that.
- For SLI to be enabled, each card needs to run at either x8 or x16. If one or more cards is at x4, you won't be able to turn on SLI.
- Z97 has 16 total lanes, which means that if you want to run dual cards in SLI, the only option is for them to both run at x8. This means that if you run SLI on Z97, you will not be able to put in anything else in a PCIe 3.0 slot, Period.
- The only possible way to use two or more cards in SLI AND a PCIe 3.0 SSD is to use X99.