Since there's not a ton of information that you've given us, there's a couple of things I'd like to recommend, just to rule things out.
The first thing I would try is change is setting all the graphics to low and see if that improves the situation. If that helps, you can gradually increase your graphics until you find the performance/graphics that you're happy with. Some users are reporting VRAM issues, so especially try out lowering the texture quality.
The second thing I would check is whether CPU, GPU, RAM or VRAM is at full capacity in the task manager. Also check you have enough diskspace left on the SSD where you installed your operating system and the SSD where you installed Battlefield. If there's no diskspace that could throttle things as well. If you find yourself at 80%+ CPU load, you may want to try out the CPU fix video by GhostGaming on YouTube.
The third thing I would check is whether my drivers are up to date and whether there's any other non-essential applications that take up too much CPU/RAM.