From what I noticed, whether playing on lowest or highest seems to not have any effect on my FPS. Regardless of my settings I sit at 20FPS around just about every building, and 30FPS in woods and ect. 3 of my friends who I play with sit at the exact same frames as I do even with our builds being completely different. 1 of my friends has a AMD Phenom II x4 at 3.8ghz with 8GB of DDR3 at 1866mhz with a GTX480 1.5gb VRAM and he sits at around 20 inside cities on low/medium spec. We switched out his GPU for a GTX 970 and its the same. So I'm thinking it could CPU related... However at the same time, he gets the exact same frames as I do and I have a GTX Titan Superclocked+, 16gb of DDR3 2400mhz, and a i7-3930k at 3.8ghz running on a 10k drive... So at the same time, I believe the problem could also be on the developers side. They did release in the patch notes 2 days ago about fixing player performance issues. However, they have been saying that for a year and a half, so I don't hold my breath for their promises anymore.