It uses the Onboard video with your PCIe video card in a sorta crossfire mode. Only works with lowerend ATI cards. As it should because the Onboard would drag down a higher end card.
Memory built into the motherboard that the onboard uses.
Well I think thats a stretch, but it can access it faster then the systems memory.
so is it like more ram?
Right, its Memory built onto the motherboard for the onboard video.