Mantle Support
The new Mantle renderer has been added in Battlefield 4. Most players can expect a performance increase by using this new low-level graphics API. Check out this news post [battlelog.battlefield.com] for the full details on Mantle, what the requirements are to run it, and how to enable it.

CPU/GPU performance and monitoring
-Tweaked and improved CPU multi-core utilization to try and avoid stuttering and low framerate due to stalls that happened on some CPU and OS configurations.
-Users can now configure and control themselves how many CPU cores should be used in the game with the new “Thread.MaxProcessorCount” settings in User.cfg.
-“Render.DrawScreenInfo 1” now also shows information about which CPU and GPU is in the system, how many GPUs & CPU cores are used and which renderer (DirectX 11 or Mantle) is active
-Added new “PerfOverlay.FrameFileLogEnable” command that records frame times on CPU & GPU and logs out to a .csv file
-AMD Catalyst driver 13.12 (or later) is now recommended instead of 13.9
-Enabled tile-based compute shader lighting optimization on Nvidia for improved GPU performance (already active on AMD GPUs)
-Improved performance with rendering and spotlights for all GPUs, primarily in in-door environments

DMR Balance Tweaks
-Increased the damage of all DMRs across all ranges. Specifically, damage has been increased at long ranges to allow three-hit kills against unarmored opponents. Additionally, reduced the penalty to accuracy for sustained DMR fire, allowing more rapid follow up shots in combat. The amount of the damage increase varies from weapon to weapon, according to its intended range, rate of fire, and damage. We will continue to monitor the effectiveness of DMRs in combat, and determine if additional action is needed to make DMRs a viable mid to long range weapon.

Other Items
-Significantly reduced the duration of the black screen when spawning in, and fixed the issue with players getting killed before being in-game
-Greatly reduced the risk of crosshairs disappearing, which would also result in hit markers disappearing
-Added a headshot icon on the killcard. This should help identify instances where players are correctly killed by one shot
-Fixed an issue in Squad Deathmatch where the “Win/Lose” text was overlapping
-Fixed an issue with players using an exploit for the SOFLAM
-Fixed an issue with players using an exploit for the MAV
-Fixed the gameplay code to properly track the FOV (Field of View) changes in the options menu
-Fixed an issue where chat would break when entering "false" or "true" in the chat window
-Fixed an out-of-helicopter glitch in Air Superiority where players could spawn on the ground and play as infantry
-Fixed the misaligned crosshairs on the T90 MBT
-Added setting to tweak joystick dead zone
-Various minor crash fixes