Mp Fps Help!!!!!!!!!

[RedWolf4000]

hey, i run 1024x768 32-bit color and textures, all details high and i get 45-150fps in single player. In multiplayer i only get around 15-20fps, with heavy heavy action, sometimes only 10fps.

My ris is as follows:

 

1ghz duron

256mb pc133

Radeon 7200 64mb (155/155)

ECS K7SEM mainboard

 

Anyone have some tips to imrove the framerate? Tried a GeForce 4 MX 440 and got less fps (because its MX of course) Plz help me out. thanks.