The problem that many users are having is that the 7000 series is not active mantle. In my 7870 does not detect if the ultim eh downloaded driver it could be a problem. Many users bf4 forums are having the same problem.
El problema que muchos usuarios estamos teniendo es que la serie 7000 no activa mantle. En mi 7870 no la detecta si eh descargado el ultim driver esto puede deberse a algun problema. Muchos usuarios de foros de bf4 estan teniendo el mismo problema.
With my HD 7770 on Windows 8.1 64 bit, I had to do the full AMD uninstall.
After that I checked the display driver and it was still using an AMD driver (maybe one that comes with Windows 8.1.). So I uninstalled that too via the Advanced Settings.
It was then using the Microsoft Basic display driver.
I installed the 14.1 beta but noticed during the install it did not mention installing the AMD display driver or the Catalyst Control center.
So (after a reboot I think) I ran it again and sure enough it installed the new display driver.
Tested Mantle in BF4 and it was all working.