Hey!
Since Bethesda don't care with the performance problem that EVERYONE is experiencing, i'm here to share the fix for the problem of FPS DROPING DRASTICALLY in Cities, where there is a lot building and etc.
The problem is the game is not well optimized, and the SHADOW DISTANCE mess everything up on the cities, lowering the SHADOW DISTANCE to medium will give you a solid 60 FPS ANYWERE on the game, i don't know why Besthesda did not fixed this BEFORE the game release, but it's fine, i hope they will release a new patch soon.
ITS NOT A HARDWARE PROBLEM. Even PCs with TOP GEAR is experiencing a -30 fps drop on cities, those who are saying: "it's your processors fault" "you don't have the minimum requiriments" are all very wrong.
This game should be very easy to run, its does not have REALLY HEAVY EFFECTS, its kind of wierd you get 60 fps on the entire freaking game but get 15 to 30 fps on cites. This is CLEARY a ISSUE.
The HIGH Settings set the Shadow Distance to 140000 and the Medium to 3000. Its a HUGE difference!
There are a lot os posts on REDDIT about it, and they suggest us to change o .INI files of FALLOUT the Shadow Distance Fade to something aroung 8000 or 10000.
Make a test! LOWER only the SHADOW DISTANCE to Medium and see the BIG DIFFERENCE that will make on your FPS.
I hope i could help some people, this trick worked for me very well. I got 50-60 FPS, no less, in the cities now,
Best Regards!