Hello... I am hoping any Mac Pro 5,1 users doing 4K work using either a GTX 980, 980 Ti or Titan X might be able to chime in. I am interested in a performance comparison of these three GPUs as far as how well they support 3-4 monitor set up AND push 4k data to one of the displays. Particularly how responsive they are at scrubbing 4k source clips or the program timeline. I'm trying to determine just how much advantage there is moving from a GTX 980 up to either a 980 Ti or Titan X. My current set up is: MacPro 4,1->5,1 2x 2.93GHZ 6-core Intel Processors 64GB Ram GTX 980 (MacVid flashed) ATTO R680 -> 8TB SSD RAID (1700-1800 MB/s reads) DP 1 & 2 - 2x Dell U2711 @ 2560x1440 (editing desktops) DP 3 - ViewSonic VP2780 4K Monitor @1080p (source and program monitoring) HDMI - Dell 2408 @ 1080P (Bin selections) (also use this HDMI output for 1080P Projector) With this set up, while I can run the VP2780 4K monitor at a higher resolutions, performance of 4k playback of the source and program monitors is reduced. Apparently the GTX980 or PCIe slot can only handle so much data. SO... would upgrading to a 980 Ti or Titan X offer a performance upgrade in this set up?