This is for anyone running a Mac Pro with three 4k displays. Mac 10.10 has know issues with interface lag. Windows stuttering, mission control lag, Swiping desktop slowness. This is seen largely on 13in MBP's and lower. 15in MBP does not have it on its own display, but it does when running one external 4k plus its retina display. How do the Mac Pros hold up? Can they run three 4k displays with multiple safari tabs, PDF's, Word or text edit documents running all at the same time with out having this issue or can it been seen on the Mac Pro as well? Please keep in mind, I'm not asking about lag in the apps themselves. Just if when you do OS functions if there is lag or stutter.