Flight Simulator X
Not surprisingly, the Radeon HD 4870 performed at the same level as the 4850 with Flight Simulator (the cards share the same drivers). They both bested the HD 3870 and even the GeForce GTX 200, but lagged behind the majority of the GeForce 8 and 9 cards. Flight Simulator X was in fact barely playable with the 4870 and the current drivers.