Massive FPS Loss in Blackreach City

[Sarcasm]

Hi, I'm experiencing a staggering FPS loss when in, near, or looking at the City area of Blackreach. This is the area with the giant ball chandelier and various buildings to enter. The best way to explain what's happening is to show it.

 

Here I am standing at the bottom of the staircase in front of Blackreach City. All four screenshots are taken from the exact same spot.

 

Looking at the city

 

Looking away from the city

 

Some more bizarre screenshots. It seems there is a certain "threshold" in the cell. Once my camera crosses that threshold, I immediately lose ~30 FPS. These two screenshots were taken from the same spot, and I slightly panned the camera left. I lost 30 FPS.

 

Looking forward, 60 FPS

 

Looking in nearly the same spot, slightly to the left

 

What could cause this sort of threshold of framerate loss to appear? I am at a loss. Pun intended. Thanks for any help that can be provided.

 

Edit: I should add that the ENB does not seem to have any affect. Turning it off still results in the same FPS loss.

Edited August 24, 2016 by Sarcasm

[Sarcasm]

Thanks for your reply, since reading your post I have been researching my weather mods. It seems it was caused by ELFX, whose meshes have some sort of incompatibility with Windows 10. This mostly fixed it.

[TechAngel85]

Are you using any mods that change the weathers or clouds and fogs?