Batman: Arkham Knight on PC boasts a host of graphical improvements not available on PS4 and Xbox One, but unfortunately the game comes locked at 30 frames per second even if your system can handle much more.
Thankfully there is a way to unlock the 30 frames per second cap, which should have you maxing your PC's capabilities in no time.
To remove the cap you need to edit the BmSystemSettings.ini found in the folder: STEAM_INSTALL_FOLDERBatman Arkham KnightBmGameConfig
Open the BmSystemSettings.ini file in a text editor and search for "Max_FPS=30". Once you've found this entry simply change it to read "Max_FPS=9999". Save and exit.
When you next load up the game you'll have have an unlocked frame rate.