Nvidia 8800(or better/higher) is good enough to run shaders. but, as the others say, its a really good idea to buy a cpu or a whole computer, otherwise you probably won't get the result you were looking for.

yup the cpu and RAM memmory has huge impact on the speed.

if though you are going to buy a new graphics card I suggest buying Radeon HD 4850. that is the one I am using and its actually totally awesome! That, with a 2.2GHZ amd Athlon I was able to play Crysis on high without lagg.

I think that you are able to play Toribash with shaders with any card with Shader model 2 or 3.

ok thanks too all now you can close this thread