I have the 7770 and its an awesome card for the price. Its the best bang for the buck, usually around $100. I have personal experience as I own the card AND I have a whole channel full of benchmarks using the card playing tons of games. Check out my YouTube Channel: www.youtube.com/thatechgamer
Heres a link for my videos for some games you were wondering about:
Crysis 3:
http://www.youtube.com/watch?v=dWyt05RPU8w
Far Cry 3:
http://www.youtube.com/watch?v=qcaNSuFUKhQ
and take a look at Tomb Raider:
http://www.youtube.com/watch?v=HodA1tTbATM
and Bioshock Infinite:
http://www.youtube.com/watch?v=iAuxZ72MEmk
Heres the link to my full 7770 Playlist:
http://www.youtube.com/playlist?list=PLD97F746F699A4982
I hope this helped, just check the video descriptions for an idea of how much FPS you should get.