I get this as well, normally on Io which I can get it to do it over and over, never fails. Once it starts I try to ignore it but it progressively gets worse until I reboot the game or just play threw it and it will sometimes correct its self even after staying on Io. I get around 150fps give or take nearly everywhere and though tit was my SLI setup but it still happens, Sometimes its on parts like in EDZ where it suddenly gets really bad, other times is perfectly smooth. I even though to my self, maybe its because I left RiviaTuner overlay enabled, even though it don't work in the game, I thought maybe its screwing around with the performance, Disabled it and it will still get all choppy just like before, Even with Shadowplay off and on its the same thing. CPU: i7 5960x 4.5ghz GPU: 2x GTX 1070 RAM: 64GB DDR4 2666mhz GPU Driver Version: 411.63 Operating System: Windows 10 x64 1803 Game is installed on an raid pair of sata based SSD's, plenty fast enough. https://pastebin.com/ur1Y2EJT