i want to get the asus a8n sli deluxe motherboard..........but it only has one pci slot and obviously that will be used by my sound card........do i need more than one............ive read about physics cards......but i dont know what kind of slot they will take up........am i better of getting the premium version with 3 slots but without the true 16 x 16 sli support(whatever that means).........thanks in advance