It gets worse the closer you are to the factory or when there's smoke displayed on the TGP. I guess it's because smoke takes up space on the screen.
I have to say that the factory it's the one named Workshop-A in the mission editor.
Factory smoke slows down my system to 1-5 fps. With previous version fps were constant around 50-70 even if factory smoke was displayed.
I think this is unacceptable.
System specs:
Intel i5 2500k @ 4.5Ghz
Nvidia GTX660