My R9 290 cannot handle Tomb Raider at Ultra 60fps

[T4Gx]

It frequently drops down to 40-50 fps but this benchmark shows it running at an average of 74.6fps.

http://www.tomshardware.com/reviews/radeon-r9-290-review-benchmark,3659-11.html

Full rig specs:
R9 290 TwinFrozr gaming edition
FX6300 w/ Antec Kuhler 930 at Stock
GA-78LMT-S2
8GB 1333mhZ RAM
XFX XXX Edition 750w

Is it being bottlenecked by the cpu? If so can I overclock it with that budget mobo to 4.2ghz if I don't touch the voltage?

 

[toprock]

t4gx now you have a 4570, can you disable the core lock fix and post up a screenshot of your afterburner after gaming. I want to see how much the default throttle has improved just by going to the intel CPU.

 

[T4Gx]

t4gx now you have a 4570, can you disable the core lock fix and post up a screenshot of your afterburner after gaming. I want to see how much the default throttle has improved just by going to the intel CPU.

This is me playing 9v9 maxed out COD Ghosts

http://i.imgur.com/qBLKe1B.jpg

 

[toprock]

Thanks for that so the core is still fluctuating everywhere, hopefully AMD will fix this in there next drivers.

Also why is the mem usage so high :- O