Multi GPU & Card Connectors

A question for whoever has any clue about it...Lets say that SLI is disabled via nvidia inspector or nhancer for FSX. (I have a GTX295 card)Alsolets say that in nvidia control panel Multi-gpu is enabled and Physx is in auto. Also my 2 monitors are connected to the 2 DVI connectors, leaving the HDMI connector without connection.Given specific fsx tweaks i get x frames.If i ONLY change multi-gpu and disable it. I get slightly more FPS but the smoothness is noticably better.And i wonderis this as it supposed to be?If i throw one of my monitors to the hdmi connector does this mean that things will be better since each GPU will take over one monitor?P.s. I know now that GTX295 was a very bad (if not the worst) selection for FSX/FS9... I am trying to find someone who plays medal of honor to sell it and get me a 580 :))))