I need some help on deciding between a single x850xt or two x1600xt in Crossfire. I know that the x850xt support DirectX 9.0b but not the shader model 3.0. The x1600xt support DirectX 9.0c and shader model 3.0, but I don't know what kind of eye candy it gives. 
I mostly play racing games like GTR, GT Legends, rFactor, Richard Burns Rally, XPand Rally and sometimes Far Cry , Half-life 2 and FEAR.
Right now I have an Athlon64 3000+ s754 with a 6600gt AGP. I plan to get an Athlon64 3500+ s939 and maybe an Asus A8R-MVP mobo within the next few months.
It seems that the x1600xt is good with games that rely a lot on shaders. So I am a little bias toward the x1600xt Crossfire wich i think will be better for the future games right ? Or is it better to wait for the upcoming x1700 series ??? If it ever comes...
Thanks for your help.

I mostly play racing games like GTR, GT Legends, rFactor, Richard Burns Rally, XPand Rally and sometimes Far Cry , Half-life 2 and FEAR.
Right now I have an Athlon64 3000+ s754 with a 6600gt AGP. I plan to get an Athlon64 3500+ s939 and maybe an Asus A8R-MVP mobo within the next few months.
It seems that the x1600xt is good with games that rely a lot on shaders. So I am a little bias toward the x1600xt Crossfire wich i think will be better for the future games right ? Or is it better to wait for the upcoming x1700 series ??? If it ever comes...
Thanks for your help.