A couple of days ago ATI secretly released a hotfix for the 4850 and 4870 series. They had claimed the the hotfix would improve overall performance and stability. Tweaktown
has reviewed four of the 4850 running in crossifreX to determine if the hotfix actually worked or just decreases performance.
The only real performance gain is in 3DMark Vantage and Unreal Tournament 3 and all of the other benchmarks have decreased like Crysis.
Check out the full benchmark at TweakTown.