Hello. I have cMP 5,1 12 core 3,46Ghz 128GB ECC Ram 256Gb Startup SSD on PCI-E and flashed by macvidcards nVidia GTX780 3GB. Since I worked only with gopro videos, everything was fine but as I bought Sony A7SII — GPU is always full and I have to close almost everything to work in Davinci Resolve. I don't like that situation, when I have to wait to close FCPX and Motion, then open Davinci, then close Davinci and open other apps again, and over, and over. It is really annoying and steals a lot of my time in total. So I decided to upgrade my gpu. As I see, the best solution I can have on inner psu is Titan 12gb. Is it really good as it has to be or better just buy 2 980ti for sli?(Does SLI have support in latest OSX - 10.11.2?!) Or maybe I have to wait a bit and nVidia will run out something new to the gpu market. All I need is fast and smooth work with UHD and 4k videos without compromisses. Thanks.