i dont know why amd cpu do so poorly when paired with 900 and 1000 series cards.
if it was only about clocks, it should be fine, but ive seen people struggle with modern games using a fx8350 @4.7mhz + 970.
like i run a 6700k at 4.5. that is arguably lower then some power house amd clocks. maybe more games are using hyper-threading or something these days and it actually makes that big a difference.