There is no denying that Far Cry is currently one of the most graphic intensive games on the market, utilizing PS2.0 technology (the latest versions support Shader Model 3.0 with DX9c) and offering an exceptional visual experience there is no denying that even some of the faster graphics cards struggle.
Far Cry (like with the new nVidia drivers) see a good performance increase but as we move down in the cards the performance increase is less noticeable. The biggest gains can be seen with the X850XT and the X700 PRO at the lower resolution.