For some reason I’m getting no more than 20 fps continuously in the Landscape Mountains level on a GTX 980 (latest drivers as of this post).
My 560 Ti can handle full screen at 60 + FPS. This is in a newly created project, no settings adjusted at all.
If I re spawn while playing, i jump up to around 60 FPS (still low for this card!), but as I get close to the water and the foliage, it plummets.