These benches tell me that if you want 4k and arnt already invested in gsync/nvidia tech ,wait for the 8gb 390x.With the 290x beating/matching the maxwell 980 in most games.Gotta imagine the revised GCN+HBM +50% shaders will be faster than the Titan-x,and defiantly cheaper.
Pretty surprised how the 290x holds up at 4k against maxwell