Upgrade: graphics card or processor?

[Shawn A]

GC: GeForce GTX 645
Processor: Intel i7-4770K 3.50 GHz
I have no idea which to upgrade.
want to be playing highly graphical games like battlefield 4 at very high, with 60 fps.

 

[rab33z]

CPU is fine. GPU needs an upgrade, depends how much you want to spend