how I use those MesaFX ?? is there any benefits if I only play older games

no no glide/openGL games works but I meant that do I have to update glide drivers if I have already installed graphic card drivers. I have DirectX 9 because glide games aren't using that API so from directX is no use for OpenGL drives

Hm, I think missing punctuation caused a misunderstanding here.

@Mansfield

MesaFX unfortunately only comes with minimal and incomplete Instructions, but they should work out to install (I summarized about all I could find alongside each Version)

If you only use old Glide or OpenGL Games that already work fine with the 3dfx Glide/OpenGL, then experimenting around may not be a good idea.

Since using updated Glide cores is very easy, however, you can easily do it by Trial&Error (as soon as you restore the original Glide cores, everything will be back to default). Some speed can be achieved with newer Glide cores in conjunction with faster CPU's.

MesaFX is mainly for new Games that don't run on 3dfx OpenGL at all (or have errors). I wouldn't use it on old games, as they usually tend to run slower or exhibit problematic behaviour in some cases.