I have a maximus vii formula and i was wondering what would be the best way to max out graphics performance. I'm thinking about either quadfire r9 295x2 or 3 way sli 980. I have heard that the bottom pci slot is only wired for 4x and it would cause a bottleneck. Don't really care about Nvidia or AMD just who will give me the highest fps in 4k. I'm planning on getting a Corsair 1500i so power is no prob.