Personally I went from two 9800gt in sli to a single gtx 460 1gb. The gains were not as great but the overhead is certainly gone. In games that only use one gpu any way will see great gains while others there will be a small margin depending on the title and drivers. The GTX560 will be able to reach much higher clocks so that can easily turn a small margin into great gains there as well so enjoy your new card.