From Hardware.FR review

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Quake Wars:ET (16xAF) Patch 1.4
9800 GTX...........101.5.................65.2 Performance hit 36.2 FPS
Ultra.................101.7.................76.5 Performance hit 25.2 FPS
GTX 260............121.3.................88.7 Performance hit 32.6 FPS
HD 4850.............86.4.................68.0 Performance hit 18.4 FPS




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Quake Wars:ET (16xAF) Patch 1.4
9800 GTX...........101.5.................65.2 Performance hit 36.2 FPS
Ultra.................101.7.................76.5 Performance hit 25.2 FPS
GTX 260............121.3.................88.7 Performance hit 32.6 FPS
HD 4850.............86.4.................68.0 Performance hit 18.4 FPS


Half Life 2: EP2 (16xAF) DX9 only
9800 GTX............98.3.................70.3 Performance hit 28.0 FPS
ultra..................89.2.................72.6 Performance hit 16.6 FPS
GTX 260............109.4.................90.0 Performance hit 19.4 FPS
HD 4850.............91.4.................73.1 Performance hit 18.3 FPS


Stalker (16xAF) deferred rendering, NO AA FOR ATI
9800 GTX............49.6..................2.9
Ultra..................41.0.................14.7
GTX 260.............58.9.................19.1
HD 4850.............49.0..................0.0


Rainbow 6: Vegas (HDR enabled) Shadows set to Low
9800 GTX............53.5.................30.4 Performance hit 23.1 FPS
Ultra..................53.1.................34.0 Performance hit 19.1 FPS
GTX 260.............60.0.................41.1 Performance hit 18.9 FPS
HD 4850.............66.6.................36.9 Performance hit 29.7 FPS


Oblivion (HDR)
9800 GTX............87.6.................51.2 Performance hit 36.4 FPS
Ultra..................87.4.................51.0 Performance hit 36.4 FPS
gTX 260.............94.7.................82.7 Performance hit 12.0 FPS
HD 4850.............80.2.................66.3 Performance hit 13.6 FPS


Race Driver: Grid (1.1 Patch) DX9 only
9800 GTX............73.4.................58.3 Performance hit 15.1 FPS
Ultra..................71.9.................59.5 Performance hit 27.5 FPS
GTX 260.............79.0.................67.8 Performance hit 11.2 FPS
HD 4850.............80.8.................70.0 Performacne hit 10.8 FPS


Bioshock Unreal Engine 3.0, Max Options, (no AA for ATI) DX10
9800 GTX............99.4.................42.2 Performance hit 57.2 FPS
Ultra..................93.9.................52.3 Performance hit 41.6 FPS
GTX 260............115.0.................57.5 Performance hit 57.5 FPS
HD 4850............119.0..................0.0


Company of Heroes DX10 Max Options Test Version 1.72
9800 GTX............51.0.................38.7 Performance hit 12.3 FPS
Ultra..................49.3.................41.5 Performance hit 07.8 FPS
GTX 260.............65.2.................57.2 Performance hit 08.0 FPS
HD 4850.............45.2.................38.3 Performance hit 06.6 FPS


World in Conflict Patch 1.0002, Options @ Max, DX10, 16xAF
9800 GTX............29.0.................19.0 Performance hit 10.0 FPS
Ultra..................32.0.................24.0 Performance hit 08.0 FPS
GTX 260.............36.0.................30.0 Performacne hit 06.0 FPS
HD 4850.............33.0.................27.0 Performance hit 06.0 FPS



Crysis Patch 1.21, High, DX10
9800 GTX............23.8.................11.9 Performance hit 11.9 FPS
Ultra..................24.1.................16.3 Performance hit 07.8 FPS
GTX 260.............26.9.................20.7 Performance hit 06.2 FPS
HD 4850.............22.2.................16.9 Performance hit 05.3 FPS


Test Bed
Intel Core 2 Extreme QX9770 Intel Core 2 Extreme QX9770
Asus Striker II Asus Striker II
4 Go DDR3 1066 4 GB DDR3 1066
Windows Vista SP1 Windows Vista SP1
Forceware 177.34 Forceware 177.34
Catalyst 8.5 Catalyst 8.5
Catalyst beta pour la Radeon HD 4850 Catalyst beta for the Radeon HD 4850

Sidenote:
If I made a mistake, let me know...thanks!