recording and playing is very taxing on your system.
im guessing you are playing the game off of your ssd and recording to your 1tb hdd?
if you just wanted to throw some money at it you could sell your 7970 for 300 and get an r9 290x.
i wouldnt reccomend crossfiring any amd card before the r - series.
another thing you could do to speed things up a little is having your 3 main tasks on 3 seperate ssd's. (operating system on one, bf4 on the other, and recording to a 3rd)
withought spending money i would get the program msi kombustor, and turn on your task manager and see whether its your graphics card, cpu or hard drives that are holding you back. prolly not your cpu but worth a check. then whichever one is running at 100% you can either upgrade the component or downgrade the quality of video you are recording.