If turning off PhysX via the launcher does not work, you can force the setting off and optimize the rendering engine by manually editing the game's configuration files.
This forces the game to load the entire X-Ray room into RAM at once, bypassing the streaming decompression lag. You will see a 2-second freeze when you first open the door, but thereafter, the fight will be smooth. batman arkham asylum x ray room lag repack
Open the launcher and the option labeled Enable OneFrameThreadLag . This single change has been confirmed to fix the X-Ray room lag for many users. If turning off PhysX via the launcher does