On every large map whenever I overlook the entire map, (from one side to the other side, like Flooded), my FPS drops from stable 91 (limit, everywhere inside buildings) to around 50-60 FPS. Now, the funny part is: whenever I look down the scope, it drops by a stable 40%! No matter what map, no matter the conditions, looking into the same spot with a scope FPS drops by stable 40% compared to looking into same spot without scope.
Example: I had 58-60 FPS without scope, I get 35-38 FPS looking into the scope into the same spot.
Problem with this FPS drop isn't the FPS I get, game is absolutely playable at 20 fps, I can get good results with 14 FPS in old single-player games, but multiplayers depend a lot on FPS, 30 is minimum for proper controls. With Ghosts, however, the problem isn't FPS value itself. Its the controls that suffer.
You see, whenever I look down the scopes, with 35 fps I get pretty fluid performance - my scope sways slowly, without hiccups/jumps/stuttering. But whenever I move the aim, it stutters as hell, visually I get around 8-10 FPS (control-wise), aim moves in large jumps, and (worst part) enemies also move in large jumps. This is a unique feature of Ghosts, in other games I get fluid performance (more or less) from 30 fps and upwards (even in older COD titles), but in Ghosts my controls start stuttering pretty bad at as low as 35 fps, only 50+ give me solid, fluid performance. As if control FPS is half of actual visual FPS...
Considering my PC (core i5 3570k at 3.5ghz, 16gb ram, GTX 780), everything should work flawlessly.
I can upload some screenshots with FPS values on maps where I have issues, if it helps.