HD 7790 is Better than GTX 650 and as per you mentioned games like Battlefield 3/4 , Crysis 3 and Test Drive Unlimited 2,
these games requires more cpu cores for better performence.
FX 6300 has 6 cores and i5 4670 has 4 cores.
those games and upcoming games will perform better on FX 6300 + HD 7790 for sure
.