Doom 3 Tweak Guide


It has been quite some time since our last game guide so what better way to return to some of our roots than with Doom 3, a highly resource intensive game with a highly configurable game engine. Perhaps not as well received as expected, Doom 3 has still gone on to massive sales.

Our Doom 3 tweak guide will take you through every option available in the game, the console, config files, graphics, audio and input settings.


The basics

To begin with ensure you have the latest patch for Doom 3 installed. This may fix any problems you have been encountering, improve performance and so on. Doom 3 features an Auto-Update option at the Menu, so use it.

It is also important to ensure you are using new drivers for your hardware and the latest DirectX installed. As before, this will generally ensure optimal performance and the least bugs possible.

Doom 3 is a very resource intensive game. If you’re not particularly willing to upgrade your hardware to improve performance, then some of our previous Tweak Guides will aid you in getting the most out of what you’ve already got.

Finally, before using any of the settings covered here be sure to enter the Options menu, select System, select Scan Hardware and Select Optimal Video Quality. This sets up many of the necessary options you will need to run the game correctly and it would be worth doing so again should you change Graphics card also.


Entering Commands

Like other id Software games, Doom 3 offers multiple ways to enter commands. Be it via the console, shortcut or .cfg (Config) files. For sake of convenience the table beneath shows how this can best be achieved using the example of enabling the frame rate counter in the game – in the guide this is referenced as com_showFPS “x”.



com_showFPS 1


com_showFPS “1”


seta com_showFPS “1”

Doom 3 shortcut

"C:\Doom 3\doom3.exe" +set com_showFPS 1


Doom 3 automatically loads DoomConfig.cfg every time the game is loaded (this is where it stores all settings). The values here are prefixed with seta as this is the value to be loaded every time Doom 3 is launched, e.g. seta com_showFPS “1”. While values in this file can be adjusted using any text editor, you can override them for a session by using other .cfg files, which we recommend you do.

By default, naming a new .cfg file as autoexec.cfg, this file will load every time Doom 3 is launched. Should you wish you may have several such additional .cfg files, e.g. sp.cfg and mp.cfg could be used to contain your preferred settings for single player and multiplayer. These can be loaded via the console using the command exec sp.cfg and pressing the Enter key. Alternatively you may want to create several game shortcuts to do this, e.g. "C:\Doom 3\doom3.exe" + set exec sp.cfg.

Regardless, any additional .cfg files use no prefix, e.g. com_showFPS “1”. Should you no longer use the .cfg file then the value in your DoomConfig.cfg will be used instead.

Creating your own .cfg file is simple. Create a new file and rename it to yourname.cfg. This can be opened with any text editor (Word, Notepad, etc.) and options should be entered like this:

image_lodbias “-0.75”

image_anisotropy “2”

image_useNormalCompression “2”

To enter commands into the console you should merely reference the table above. For quicker access to the console open your Doom 3 shortcut properties and add:
+set com_allowConsole 1, e.g. "C:\Doom 3\doom3.exe" + set com_allowConsole 1.
This allows you to access the console by pressing the Tilde ‘~’ key (default is Ctrl+Alt+Tilde).


Benchmarking/Recording Demos

Doom 3 features passable benchmarking features, although it’s restrictive enough as to their relevance, or as John Carmack put it recently – “Timedemo doesn't do any game logic. Demos are always recorded at exactly 30Hz That and the frame rate is by default limited to 60Hz, as such benchmarking will always yield better performance than you will actually get in the game so bear that in mind.

Regardless of all this, benchmarking is still the best way to tell how effective your new customs settings are performance-wise, e.g. the results beneath indicate I’ve been a bit over-optimistic as regards using higher quality graphics settings.

Benchmarking is carried out by entering commands into the console, the use of which was discussed in the previous section. Relevant commands are as follows:

recordDemo “x”. x specifies the name of the demo you wish to record, e.g. recordDemo mybench will begin recording (At 30Hz per second) a demo named mybench. It goes without saying that for a benchmarking demo that you should try to record a section with a good deal of enemies to fight or lots of lighting.

stopRecording. If you were expecting this command to do more than the obvious then you were wrong, it just ceases recording the demo you had initiated with recordDemo “x”.

playDemo “x”. x specifies the name of the demo you wish to playback, e.g. playDemo mybench will load the mybench demo.

playdemo stop. This command ceases playback of the demo loaded with playDemo “x”.

timeDemo “x”. This is used to benchmark the x demo, e.g. timeDemo mybench. The results are displayed after the demo is run, with the average frame rate being determined by the number of frames in the demo divided by the seconds it took to render them. It is worth noting that a timedemo should be performed twice in order to get accurate results, on the initial run data will most likely need to be loaded – which will be cached for subsequent runs.

timeDemoQuit “x”. This operates exactly as timeDemo “x” previously, albeit instead of displaying results when finished the game quits. Not too sure what the point of this would be.

Now that you know how to apply settings in the console and benchmark the game, let’s go onto the options themselves, which I’ve broadly categorized into Graphics, Audio and Input.


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