Bf4 Fps drops all the time even if you have a good PC, Gulf of Oman drops fps the most and in particular Op Metro and Locker with that explosions. DICE is working on that. FPS of Bf4 because of Netcode, when 64 players are blowing everything then the servers cant cope with it as tick rate is very low for Bf4 servers, this causes the client to lag and get fps drops.
If you played Bf4 from the launch you already know this. If there is any solution for this problem then please Share. Over million ppl are suffering.