Those two cards pretty much trade blows with the 4850 being a little faster as Turtle1 said. My only grip with the 4850 is that most models are single slot solution which is not the case with the 9800 GTX+. This helps keep things a little cooler. IF you're willing to spend a little more some, you should get a none reference 4850 equipped with a better cooler. I know HIS has few models that seem interesting. The 4850 has a tendency to run hot so a better cooling system is certainly a good idea beside the fact that the heat get expelled from case.