I'm not too sure on what causes very heavy frame drops down to 38-45 fps, and it's been persistent in most of the past updates, but I think it's the bathroom mirrors. I only get big frame drops when looking in the direction they're both in. I've changed my settings from lowest to highest, but I only get maybe 5-6 frames more in the lowest. (I can easily handle a stable 60fps anywhere else). I shouldn't be getting this low of an fps drop anywhere with my PC specs.
NVIDIA GeForce GTX 970
Intel i5-6600K @ 3.5GHz