I am planning to use this motherboard, the ASRock X79 Extreme6 ATX LGA2011 Motherboard, as well as 3 7950s and a Revodrive. There are 3 x16 PCIe slots on the motherboard, so I need an extra slot for the revodrive. Is it possible to use a splitter, or should I just just 2 GPUs and the Revodrive? If so, the GPUs have x16 PCIe connectors, but the Revodrive has a x4 connector. Will I need an adapter or are they compatible?