Try a clean boot: http://help.ea.com/en/article/how-to-clean-boot-your-pc/
Also, try looking at your memoryconsumption using the method described in here: http://answers.ea.com/t5/Battlefield-4/Possible-solutions-INFO-REQUEST-NP-Pool-Memoryleak-PC-only/m-p/1951455#U1951455 and tell if there's any changes when the low fps begins.
If clean boot works you have an application running that is causing the problem. You should figure out which one it is 🙂 Since you havn't done it I'll mark my post as the solution to help others with the same problem.
i have the same problem but guys ,, when i make fast boot and restart PC .. i see network is disabled and i can't even open Battlelog or origin
to try if that helped me or not :\ can someone help me about that ?
Ive had the same problem for about the last three weeks. BF4 just started running with low FPS after afew minutes play. I shut the browser and it fixed everything. I was using Firefox so Ill have an experiment with other browsers and see if they do the same.
