With two nVidia GTX 1080's I have run XP v11.0b8 with "Force alternate frame rendering 1" to a 4k monitor - will see perhaps 2-3 FPS faster than running a single GPU. On other CPU/GPU intensive games, there'll be a 40 to 50% increase in FPS (this over a single GPU). So I'd save your money for now - wait until this issue has been resolved. There seems to be some "pipeline" bottleneck between the CPU's and GPU's. In my system both the CPU and GPU show a low percentage of utilization.