High Quality AA and AF
Our high quality tests let us separate the men from the boys and the ladies from the girls. If the cards weren't struggling before they will start to now.
Aliens vs. Predator performance is just too low with AA and AF on. Mafia II performance is just absolute border line. Drop the AF or AA down slightly and you would get playable numbers with some good eye candy.
As for SF IV and Far Cry 2, you've got some great performance and both games have no problems playing with these settings on the Palit GTX 550 Ti SLI setup.