Based on the program written by Dan Kennedy at Tweak 3D.Net

Quake 3 Autoexec creator

This program will allow you to customize your Quake 3 game in order to optimize performance and visual quality. If Quake 3 runs slow or poorly for you, check the boxes you wish below, then click the "Create" button to create an "Autoexec" that will customize your game. 

1. Level of detail: The Level of detail (LOD) will configure the detail of weapons and objects. This will lower visual quality, but it will boost frame rate (how smooth a game runs, measured in FPS: Frames Per Second) and make the game run better. If you set the LOD to 2, your gun will look much uglier, but the game will run better. The default value for this option is LOD 0.

        

Use LOD 2 (unchecked = LOD 0; default)       

 2. Simple items: Enabling "Simple items" will boost performance by hiding the small bubbles that contain energy, and rings that contain quad damage and other items, like weapons and ammo.

        

Hide bubbles and extra rings (unchecked = disable simple items; default)        

3. Gibs: Gibs are the flesh remains that stick around after a player is killed. Disabling gibs will boost   performance.

Hide gibs (unchecked = keep gibs, default)

4. Dynamic light: When you fire a weapon in Quake 3, it throws light on the walls and surfaces around you. This effect is called dynamic light. If disabled, it will boost performance significantly. See the screenshots below. Look at the differences between the overall lighting in the scene. This is a major performance boost.

          

  
         

Disable dynamic light (unchecked = enable dynamic light, default)

5. Marks on walls and surfaces: Most weapons in Quake 3 will leave bullet holes or scars of some type on the walls and surfaces. Disabling this effect will boost performance.

Disable marks on walls (unchecked = enable marks on walls, default)

6. Weapon visibility: You can hide your weapon in Quake 3, which will leave the crosshair visible. You will be able to see more of the area by hiding the weapon and this will boost performance.

         

Make weapon invisible (unchecked = leave weapon visible, default)
    
7. Sky quality: The sky in Quake 3 is very impressive, but has no effect on the way the game plays. If disabled, it will boost performance significantly.
See the screenshots below. Look at the difference in the backgrounds. One has a flat, plain background, while the other is very detailed. Setting your system to "fast sky" mode will result in a large performance increase.

         

Use fast sky (unchecked = high quality sky, default)

8. Shadows: Shadows in Quake 3 are shaded regions that look similar to real shadows, that are cast from most objects, including player models, gibs, and walls. There are a few options for shadows in Quake 3. Setting the value below to 0 will disable shadows completely. This is the default setting, and I recommend you use this for the best performance. Setting the value to 1 will enable plain shadows which look out of place, and significantly slow the game down. If you set the value to 2, the shadows will be stencil buffered. This is a technique that creates very realistic shadows in terms of lighting but this slows the game down a lot. Setting this to 3 will also use stencil buffer shadows, but they will be somewhat darker. If you set this vlaue to 2 or 3, it will also configure the r_stencilbits variable. Keep in mind that stencil buffering is not supported by all video cards and therefore I do not recommend that you use it.

We recommend setting shadows to 0

 9. Gamma: Gamma is the measurement of brightness. If Quake 3 is too dark or too light, try adjusting this value to your liking. The default value is 1. This value can be set as low as 0 or as high as 3. Setting this higher than 1 with increase the brightness and lowering the value will decrease the brightness.

We recommend that you set this to 1

10. SMP: SMP, or Symmetric MultiProcessor support, should only be enabled if you have more than one CPU in your system. This is uncommon for most computers, so make sure you have more than one CPU before enabling this feature. If you do have more than one CPU, this will boost performance considerably.

Enable SMP (unchecked = disable SMP support, default)

1. Maximum frame rate: When playing over modems, lag is unavoidable. The best way to eliminate some lag is to limit your frame rate. Setting this lower will result in lower pings - but also frame rates. My favorite setting is between 30 and 33. If your modem is slower, you may have to set it lower. If your modem is faster, try setting it higher. Non-modem users should not be concerned with this command.

Maximum modem frame rate (default = 0)
  
2. Rate: Another way to battle lag is to adjust the rate. Setting this lower will result in lower pings in most cases, because the servers will be sending you less data. With my 56k modem I set the rate to 3000, which is quite low, but works great for me. I recommend setting this to between 2500 and 3500 for 28.8 or 33.6 modems, 3000 to 5000 for 56k modems, and 5000+ for other, faster connections. For LAN (local area network) games, set this up to 25,000. Try different values and pick what works for you.        

Set the rate value according to your Internet connection speed

3. Netgraph (Lagometer): The netgraph is enabled by default, and shows the lag on the server you're on. This can cause a distraction but I recommend that you leave it enabled.

Disable netgraph (unchecked = enable netgraph, default)

4. Message time: Although this doesn't really relate to performance, it's something that most people would prefer to customize. Set this variable to the time in seconds that you wish messages to stay on your screen before disappearing.

Time in seconds (default = 3)

1. Sampling rate: The sampling rate of sounds determines the overall quality of the sounds heard during the game. This will also lead to more CPU usage and therefore slightly lower performance. If you have a high quality sound card, set this to the highest value.

You have to set this to one of three settings: 11, 22, or 44 (default = 22)       

2. 8-bit sounds: To save on memory, sound card, and CPU load, you can set the sound files to load as 8-bit. This can boost performance, especially on slower systems. It also will result in less hard drive access. However, this will lower the sound quality.

Enable 8-bit sounds (unchecked = 16-bit sounds, default)

1. Show frame rate: Your frame rate will determine how well the game will run. Any frame rate lower than 30 will not be completely smooth. Enabling this option will allow you to view your frame rate. If the value is very low, try some of the settings above, or try lowering the games resolution.

Show frame rate (default = disabled)

2. First person view: If you don't like the standard first person view, you can enable third person view. Third person view is much like having a camera following you around at all times. I think it is much harder to aim like this.

         

Use third person view (unchecked = First person view, default). If you dislike first person view, I recommend you try this.

3. Reserved memory: You can set a desired amount of system memory, or RAM in MB, for Quake 3 to allocate. This will usually lead to better performance because the memory will be allocated to the game. Make sure not to choose more memory than you have available.

Allocated memory (default = 30 MB)

4. Console speed: The console (toggled up and down by hitting the ~ key) is used for several purposes. By default, it slowly moves its way down and up, wasting precious time (and in some cases endangering your life). Increase this value to cause the console to come down and go up faster (or lower to cause the console to go up and down slower). The default value is 600. A value of 3000 or higher makes the console come up and down almost instantly.

Console speed (default = 3). I recommend that you set this value to 3000.

5. Joystick: Most people find it easier to use a mouse/keyboard combo rather than a joystick when playing first person shooters like Quake 3. Disabling joystick support will increase performance.

Disable Joystick (unchecked = enabled, default)

Follow the instructions in the window that appears after clicking the Create button.