cod advanced warfare stuttering on my hardware

[chris AMD]

I have a fx6300 cpu clocked @ 4.4ghz.
r9 270x 2gb clocked @1150mhz
8gb system memory 1600mhz.

Cod advanced warfare stutters in game play and prerendered scenes when I have settings set to extra. on high its pretty smooth with only a little stuttering in game play. In my case, what is likely cause? my cpu, not enough video memory, or not strong enough video card? Im playing the game at 768p resolution. I already have shadow cache settings off.

 

[Cons29]

probably gpu, not sure how things have changed for COD (they were not that demanding historically), but a 270 is good, but not that good.
so setting things to extra might be too much for it