I had issues as well with Mantle on BF4 with my R9 390x which has 8GB of VRAM. I have Win 10 and an FX8370. This was before the 16.9 firmware though. I have been running DX11 since my issues. Title says 16.9.2 but your specs show 16.9.1.
Also, on the release notes for the latest driver: "
- Battlefield™ 4 may experience intermittent crashes when using Mantle. As a work around users are suggested to switch to DirectX®11
Yeah I forgot to add the - 16.9.2 as well tested both of them.