Read this driver readme for ex:
http://www.nvidia.com/object/win7-wi...ql-driver.html
For ex. performance boosts for specific card in specific games, those boosts just don't appear out of thin air. Sli and Crossfire implies that 2 or more gpu`s have to work together and not against each other, that doesn't just happen on its own. Not all games work the same way/is coded the same way hence different profiles to get maximum boost. Sli does work with global settings but not as good as it can with a specific profile. (witch in tales more than just pre defined settings made in the control panel)