I wanted to eventually get a second graphics card to work in SLI, but my Motherboard only has 1 PCIe 3x16. It does however have PCIe 2x16 and i was curious since PCI is backwards compatible, would it be capable running SLI using 3 and 2? Ive read that the difference in performance across 3 and 2 isn't much, like 5-10%, but i want to know if they can sli together before i drop some more serious cash XD