Originally Posted by morbias
the FX 5xxx family has pretty poor shader performance, and farcry uses these shaders loads. which is, unless you own a 6800, quite a performance killer. However, if you open the Farcry configuration tool and select 'customize', you can edit nearly every parameter the crytek engine supports. as Kev1 mentioned, find a tweak guide that centres on the configuration custom options and you should see a big speed increase without losing too much quality
The 59xx series cards are in a higher league of performance than the other 5xxx cards you speak of. And the 5900nu on up, run all the games he mentioned perfectly fine.