EA DICE is deploying a Battlefield 4 update for Windows PC today, according to a post on the Battlelog forums, improving CPU/GPU performance and monitoring, introducing Designated Marksman Rifle balance tweaks and addressing numerous issues.
The patch will introduce bug fixes for a number of problems such as reducing the risk of crosshairs disappearing and issues with players exploiting the SOFLAM and the MAV. The damage of all DMRs across all ranges have been increased and now allows three-hit kills against unarmored opponents at range and the penalty to accuracy for sustained DMR fire has been reduced. The developer will continue to monitor DMRs to make it a "viable mid to long range weapon."
Today's update also introduced the delayed Mantle patch, an API designed to improve a game's visuals and how efficiently it's rendered. Full instructions on how to enable Mantle, along with further information about expected performance improvements, are outlined on the blog post.
The full list of Battlefield 4 patch notes for the Windows PC are detailed on the Battlelog forums.