The AMD Mantle driver (AMD Catalyst 14.1 Beta driver) should have been released with the latest Battlefield 4 patch with Mantle support. But the driver was not released on time due to a last-minute delay caused by too late detected driver issues. That´s why AMD did hold back the driver.

AMD wrote “We are putting the finishing touches on the AMD Catalyst™ 14.1 Beta driver, which enables support for Mantle and many other fabulous features. We appreciate your patience and will update you as soon as it’s ready for download!”. While we still don´t know for how much time the driver will be delayed, it is sure to say that you will see the download on this AMD beta driver page soon.

UPDATE: AMD released the Catalyst 14.1 driver now.