AMD's hUMA is going a different direction where CPU/GPU can share resources in system memory, and ideally, in VRAM as well. Though, AMD are already moving toward HBM and other things for the GPUs to increase bandwidth. All the while they are increasing compression to make more use of the bandwidth they have access to, and things are looking pretty bright at this point on that front, some game changing things should be coming forward in the next 12-18 months on all fronts for them across the board.