I am building A new gaming rig. I am purchasing the Corsair AX750 PSU and it has 4 x PCIE 6(8) pin plug ins. I am getting 1 Msi Twin Frozr II 570 right now and another one in a month for SLI. It requires 2 6 pins each. Will I be using my 6 or 8 pins for anything else or can I use all 4 with both of my GPUS...thanks guys