I'm building a mining rig with two GPUs (And hopefully 3 at some point), but the motherboard won't boot if two GPUs are in. If I put only either one in, it boots fine. My motherboard is from a XW4400 workstation, and has 4.5GB of DDR2 with a Q6600. It has 3 PCIE slots, an x16, an x4 with x16...