X99 is the superior option with tri-sli if you go with a 5930K. That CPU has 40 pci-lanes natively. You will have to get a PLX chipset on a Z170 mobo for 40 oci-e lanes, which will add latency. Some people do not notice it but I did, and thus upgraded from Z77 to X79. It was worth it IMO, and I only run 2X sli. YMMV.
2/28/16 at 2:13pm