To answer your question, coming from the 4.4 build, even a 1080 Ti would not get you a solid 60fps all the time, so you have to know that you'll be sacrificing a few frames just so that you can call it playable. And this is at 1080p too. So 4K is definitely out of the question. We have even tested it on dual 1080 Tis with mixed results. So while it will be playable, expect stutters and an uneven fps count all the way through.