HD 7770 and GTX 650 are of same type.But HD 7770 is slightly better than GTX 650 and less priced than GTX 650,.I have Sapphire HD 7770 1gb GDDR5 and i can play all games at high-med settings..Here are some frame rate details
Battlefield 4 at ultra anti aliasing off - fps 35+
Far Cry 3 ultra - fps 40+
Watch Dogs Med-High settings,fxaa - 25+fps (this game is bad pc port)
Crysis 3 ultra anti aliasing off - 35+fps
fifa 14 ultra 60+fps
and i played many games and i cant list all of them here.It is really a good budget card...And you can play even the high expected game GTA V (releasing on november 14 for PS4,XB1 and PC) on med-high settings.Better go with the HD 7770.You may get extra 2-4 fps with HD 7770 and you can overclock it tooo...I...