[HD7850 2GB] vs [Crossfire Dual 6770 1GB x2] vs [SLI Dual GTX 550ti x2] performance?

[gsdgsag]

Out of the three setups, which has the better performance?

HD7850 2GB, vs
Crossfire Dual 6770 1GB x2, vs
SLI Dual GTX 550ti x2

 

[jonnyp11]

7770 x2 would be best probably but a 7850 2gb would be smart and you could get a second in a few months

 

[gsdgsag]

7770 x2 would be best probably but a 7850 2gb would be smart and you could get a second in a few months

Good idea thanks