Just out of interest, are you using the latest 14.9 drivers from AMD?
download DDU and uninstall all your drivers completely. ( Safe Mode ), then install driver and see how that is.
Let me know how you get on trying the 2nd PCI slot mate.
I play battlefield and loads of my friends and none of us have heard of that or get problems like that on the game. He also gets the problem on another game so it can't be down to Battlefield. Also there is nothing about it online. Its not down to BF4 i don't think Daz.
Do you have another pc to try the card in?