@paraskhosla:
Before gaming, and checking for FPS, please check that the slave card is even kicking in and being stressed. 5xxx series are still facing issues due to the drivers maturing. Keep the setting ON, so the XfireX icon appears on the top right hand of your screen. Xfire is tricky to get to work, but great once it kicks in. Would suggest the following:
1. Install RivaTuner, and choose the GPU 0,1 Usage% option. Leave it running in the background (or minimize it). Run 3D Vantage, and play some games. Then review the usage.
2. Stress your system. Using OCCT/Furmark.
3. Though both your cards are exact, verify that all engine/memory speeds are exact matched.
4. Evaluate temperatures.
Also for your knowledge, regarding cross fire bridges. I tried the following combinations:
1. One bridge first bank.
2. One bridge second bank.
3. Two bridges on both banks.
I did this with the motherboard Xfire bridge, and the GPU bundles bridges. There was no difference in performance. Again this is a debatable school of thought. You can google "how many cross fire bridges". You will see mixed reviews/suggestions.
Enjoy the Xfire. Way to go...! Congratulations. Also if you get time, post some benchmark results of Vantage, and Warhead Benchmarking tool. RE5 if you got it. Would be nice to see the power of your system.