Quake 3 is a complex game and pushes processors and Graphics cards to there limits the aim of this section is to get the most out of your Graphics Card when using a modem. Smooth scrolling will help when playing using a modem. To start off with below is a list of pointers then its configuring Q3, console commands, and autoexe.cfg files.
Find out who makes your Graphics Card and download the latest drivers for it.
Turn off any CPU hungry programs when playing Quake III.
Been playing games or using apps, if your Memory is small less than 128MB a reboot before playing can help game speed.
Why Tweak ?
The main reason for tweaking the graphics in Q3 is to get the game to run smoothly at 125 frames per second why ? 125 frames per second seems to be the optimum speed for the Quake 3 game engine to run at. Your Quake III model jumps further and moves smoothly at 125 frames per second. The mouse samples nicely at 125 samples per second some Quake 3 Arena players set there maxpackets at 125 and snaps at 66 half 125.
How To Tweak The Graphics
Any graphics card equal to or less powerful than GF2 MX will need tweaking. At least an AMD 750 processor is needed to smoothly maintain 125 frames per second with a few players on the screen. One of the best ways to improve the frame rate is to buy a new graphics card even a cheap GF-FX card will run Q3 Arena nicely at 125 frames per second with a mid range processor.
If your using a slow graphics card and processor use the autoexec.cfg generator on this site to get the best frame rate. The autoexec.cfg generator is better than using Quake 3 Arenas in game menus for setting up the graphics etc because it uses variables not available in the game menus like removing gibs,blood,lighting effects, weapon effects etc etc. wheres removing these effects don`t individually increase frames per second that much they add up when used together.
Tweaking To Win
Q3 Arena players players also tweak the graphics`s so they can see other players more easily by changing the lighting to vertex reducing the texture quality. Removing players blood ,spent ammunition in game video screens, gibs,lighting effects, weapon effects. All the above while looking good can detract from the main point of the game which is fragging everything that moves as often as possible. Use the autoexec.cfg generator to set the game up for the best visual setting for on-line play.
Lightmap Turned On
Vertex Turned On
As you can no doubt tell by looking at the pictures above with vertex lighting turned on you can see more easily.
Getting Started
Find out who makes your Graphics Card and download the latest drivers for it. 
How To Tweak The Graphics
Tweaking To Win
