A couple of days prior to the 1.4 update, performance in-game seemed to tank.
I was getting 80-100 fps reliably before this.
Current performance hovers around 30 fps, often struggling to get even that high.
I've played with settings, and texture streaming memory to no avail.
Let the game autodetect, used the high and low presets, nothing. It seemed to make no difference at all, actually.
I'm running a 6600k @ 4.2, a 1660Ti, and have 32Gb of RAM on this machine.
Apparently, other people are having these issues too, but not everyone.
I'm at a loss for what the issue could be.