Try different values here, 4, 6, and 8 all improved performance for me, but 8 is the best for my hardware (i7-4790K). If I'm not mistaken, this allows the engine to open up more threads on your proces
Good luck in Murkmire, then. One of the towns there has me crawling at 20fps on the relatively stable PTS server, compared to my 70ish in Mournhold on live. So many assets.
I wouldn't recommend getting a 4K monitor with a GTX1080. If you really want to game at more than 60FPS (or locked 60 with all newer games in max settings) you gonna need a 1080Ti (minimum) or one of