As Ecky said, not an A8 or A10, just an X4 860/870/880K. Its the same CPU as an A10 but without the integrated GPU. With the X4 860K you can get very decent results, medium settings at 1080p: https://www.youtube.com/watch?v=9Xoay7XBIlE
It's not really a bottleneck, it's just the game is very CPU dependent and the A6 is only a dual core, and a very weak CPU too. You could upgrade and getter results with a X4 860K , which is a quad core.
If you're using a discrete graphics card, there's little point in buying an APU. You can probably find an Athlon x4 which is the same CPU but with the integrated graphics (which you're not using) disabled, and at a much lower price.
EDIT: FM2+ quad cores are still very slow by 2017 standards but would be hugely better than your dual core.
As Ecky said, not an A8 or A10, just an X4 860/870/880K. Its the same CPU as an A10 but without the integrated GPU. With the X4 860K you can get very decent results, medium settings at 1080p: https://www.youtube.com/watch?v=9Xoay7XBIlE