I do not know what you have now.
But, if you already have a FX of some sort as well as a GTX970, I think you are unlikely to see any difference using a FX-8320e.
For example, a FX-6300 has a passmark rating of 6345 and a single thread rating of 1409.
The FX-8320e has a passmark rating of 7430 and a single thread rating of 1350
Few games can use more than 2-3 cores, so the extra cores are not helpful. Possibly helpful if your BF4 is multiplayer.
But really, most games are dependent on the strength of a single master core so I would expect no real change.