Please don't kill me on the spot. I know I'm number 23084203948 with this thread. I have read a LOT of them. I've installed eVGA GTX 980 Ti into my mid2010 5,1 mac pro. Both power sockets are connected. 32G RAM, 2x quad-core xeons. With 2x 4k displays working in 2k mode (2560x1440) desktop rendering speed (chrome, slack, basic apps, whatnot) is very sluggish. Games work well, just that the desktop lag is horrific. Even when scrolling in a single long page in chrome I can see pieces of the page render with my bare eye. My MBP mid-2015 with stock video card performs better. Latest web driver is installed, so is CUDA. What am I missing?