Steam said that Call of Duty: 2 won't support the 6850, but I'm pretty sure that it is better then the GTX 560Ti, here are the "Supported Chipsets"
Supported Chipsets
ATI Radeon 8500
ATI Radeon 9000
ATI Radeon 9200
ATI Radeon 9500
ATI Radeon 9600
ATI Radeon 9700
ATI Radeon 9800
ATI Radeon X300
ATI Radeon X550
ATI Radeon X600
ATI Radeon X700
ATI Radeon X800
ATI Radeon X850
nVidia GeForce 2 Ultra
All nVidia GeForce 3/Ti Series
All nVidia GeForce 4/Ti Series
All nVidia GeForce FX Series
All nVidia GeForce 6 Series
Recommend nVidia GeForce 7 Series or higher
Do you think that I could run CoD:2 with my graphics card, or do I need a different one?
Supported Chipsets
ATI Radeon 8500
ATI Radeon 9000
ATI Radeon 9200
ATI Radeon 9500
ATI Radeon 9600
ATI Radeon 9700
ATI Radeon 9800
ATI Radeon X300
ATI Radeon X550
ATI Radeon X600
ATI Radeon X700
ATI Radeon X800
ATI Radeon X850
nVidia GeForce 2 Ultra
All nVidia GeForce 3/Ti Series
All nVidia GeForce 4/Ti Series
All nVidia GeForce FX Series
All nVidia GeForce 6 Series
Recommend nVidia GeForce 7 Series or higher
Do you think that I could run CoD:2 with my graphics card, or do I need a different one?