Though not offifically confirmed, word is out that AMD Mantle Update For Battlefield 4 was delayed. It seems that DICE still has not worked out technical issues, gameplay and stability. Initially everybody expected the Mantle update in November, then it became December and then it was delayed to January. 

Here's a snippet of what wccftech reported on this:

Battlefield 4 is DICE’s flagship title and is a great game when it works but there are several issues which are yet to be addressed causing disappointment among the vast fan community DICE has amassed over years. Battlefield 4 has received several updates over the last two months on next generation and PC builds which have improved the performance of the game but the netcode itself remains optimized and causing several gameplay issues. DICE has already delayed all work on extra content such as DLCs and also the highly anticipated Mantle update which was announced several months ago. A chat log with EA’s support reveals that the update has been pushed to next month.
We have yet to see an actual game utilizing the Mantle API which leverages performance of AMD GCN based hardware. The AMD Mantle API is being exclusively developed for GCN enabled Radeon graphic cards.

This would allow developers to dig deep into the metal to bring console-level optimizations through ease of programming and faster optimizations over a coherent GCN chip architecture. This means that we would see better performance on the entire GCN architecture enabled AMD graphic card lineup ranging from the top Radeon R9 290X to the bottom R7 240.

Meanwhile tweaks from AMD and even DICE dispute all this. There still is a rumor of a driver release today or tomorrow and a BF4 DICE update planned later this week. Ah who knows ....

AMD Mantle Update For Battlefield 4 Delayed ?