I am running that combination and all of the games that I have tried look good to me, I don't benchmark or pay attention to the FPS numbers. I may just not be sensitive to slowdowns, but I just played through Bad Company 2 and it looked fluid as can be with all the settings on the max. If it does get to the point that it bothers me, I'll get another 670 and go SLI. But again, I don't set around and fret about framerate numbers, I just enjoy.
Ivy Bridge Rig - 16GB Crucial PC1600
3770K@4.3 CM 212 EVO - Gigabyte Z77X UDH5
EVGA GTX 780TI OC/ACX with Dell U3011
Antec 300-2 with ANTEC 850psu
Samsung 830 128gb SSD- 640gb Western Digital Black