Performance Tweaks

For Players

This article relates to performance issues for players. For performance information for mappers, see Performance: Essential Must-Knows

Minimum Specifications

CPU: 1.5Ghz with x64 instructions (64-bit) and SSE2 SIMD support
GPU: OpenGL 3.2 compatible with at least 512MB of VRAM ( roughly the performance of a Geforce GT 8800 )
RAM: 2GB+
Storage: 30GB free space ( depending amount of missions you download )
Display: We recommend a display that can render at least 640x480 for legible menus and hud.
(Some analog NTSC televisions with 480i have high quality sub-pixels that can render an image that looks approximately like 1024x480 or 800x480.
If you PC has analog TV out, try configuring 800x600 or 1024x768 resolutions for improved fidelity.)

You may be able to play on weaker hardware using config tips in this wiki but you will likely encounter many missions that are too taxing.

The Dark Mod 1.0 was originally released in 2009. The average mission designer and player of that time had a Geforce 6600GT and AMD Athlon 64 X2 2GHZ.
While some missions were playable all the way down to a Pentium 4 2.8GHZ with a Geforce FX 5200, this is well below the expected audience for this project.
Current Intel integrated GPU's have better performance than the Geforce 8800 (which was a very high-end card in 2009).
( Low-power mobile chips are known to throttle under heavy load, especially when using integrated graphics. )

See Hardware Considerations for additional details.

Conventions

Most of the changes demonstrated in this article are via "Console variables" CVARS.

The "seta" prefix is intended to save these settings permanently so that they are retained on restart and that is what is used by Darkmod.cfg.

Note: With the exception of Screen Resolution and Image Downsize, most settings can be changed in realtime in the console or via a key bind in DarkmodKeybinds.cfg.
(Also, "Render Scale" can be changed in realtime and is preferred to Screen Resolution anyway)


seta something "value"

OBSOLETE Suggestions

Some configuration suggestions in this wiki are no longer applicable in the latest TDM versions and are only
preserved for players running old versions. Where applicable these are labelled OBSOLETE so you can ignore them.

Temporary Testing

To temporarily test any settings, you can drop the "seta" and simply invoke the cvar and it's value (without double quotes) in the console.

Example:

Open the console with Ctrl+Alt+~ (tilde, ^ on German keyboards) and type:


r_softShadowsRadius 2

Toggle settings in realtime

For example, you could bind both shadow maps and soft shadows to the Z key to enable and disable them both by pressing that key


bind "z" "toggle r_shadows 1 2; toggle r_softShadowsQuality 0 15; shadowimplchanged"

in DarkmodKeybinds.cfg

( shadowimplchanged is needed when changing shadow modes )

Mission.cfg (New in 2.12)

When TDM was a Doom 3 mod, you could add a DoomConfig.cfg file to specific missions under doom3/darkmod/fms/mission_name
This allowed you customize settings on a per mission basis
In TDM 2.12 a new config file called mission.cfg was created that allows mission authors to make fleeting setting changes to dynamic cvars
You can use this file to replicate the old per mission concept

Make a mission.cfg file and place it under your darkmod folder. This is your global setting file.
Make another mission.cfg file and place it under darkmod/fms/<mission_name>. This is your per mission setting file
Add cvars to the per mission file in the format of seta r_something "0"
For each cvar added to the per mission file, add the preferred default version to the global setting file

To ensure the global setting gets re-applied, uninstall the current mission before installing a new one

Launch Options

You can also add the value as part of your target in your shortcut:

Example with two cvars:

Right click your Desktop shortcut to TheDarkMod and select Properties
On the Shortcut Tab enter the following into the "Target:" field


"C:\darkmod\TheDarkModx64.exe" +set r_softShadowsRadius 2 +r_useEntityCulling 1

(Assuming you installed into C:\darkmod)

Then click the Change Icon button and browse for the Darkmod.ico icon in your darkmod install path
Click Apply

Evaluation and Diagnostics

The following options offer basic quick tools to examine performance.
See Profiling and Tracy Profiler for advanced (developer level) performance evaluation

Show FPS

First, you can check how many FPS are achieved by opening the console with Ctrl+Alt+~ (tilde, ^ on German keyboards) and type:

com_showFPS 1

Show Position

To identify the locations where problems are found, use these two cvars to render the positions as an overlay display while playing.

Open the console with Ctrl+Alt+~ (tilde, ^ on German keyboards) and type:


g_showviewpos 1

con_noPrint 0

TDM Show Viewpos ( New 2.12 )

To accomplish the basically the same thing ( a little more refined ) the new tdm_show_viewpos cvar is now available


tdm_show_viewpos 1

Stop Time

Moving and Thinking can impact performance in unexpected ways.
When comparing graphical settings it might be best to "Stop Time" so that the entire scene is frozen
and the FPS changes due to graphics options can be more easily compared.
Open the console with Ctrl+Alt+~ (tilde is ^ on German keyboards) and type:


g_stopTime 1

Killmonsters

You can roughly estimate the impact of AI by navigating to an area or room where no AI are visible, then invoking "killmonsters" in the console
If the FPS jumps up dramatically, your performance issues may be mostly related to AI think cycles on the CPU

If so, try TDM config changes that can reduce CPU usage such as "Shadow maps mode", "Lightgem interleave", "Disable EFX", "2.03 Search Behavior",
"Disable Lip Sync", and "Skip Particles"

( Make sure Multi-core , Frontend acceleration and Uncapped FPS are enabled and ensure your OS is optimized too )

No Shadows

If you disable shadows and there is no performance change (especially if you also killmonsters ), this can indicate something more complex is impacting performance.
While shadows are off, try lowering and raising individual quality settings and see whether any have dramatically different performance impact.
If not, raise the issue with mission author in the original mission thread ( unless the mission is already known to be taxing )


r_shadows 0

Delete Darkmod.cfg after upgrade

If you run tdm_installer to upgrade TDM, it offers you the option to Restore Darkmod.cfg.
When you do this, you may be reverting newer configuration defaults that have been changed in the latest release.

While it may be inconvenient to reconfigure all your preferred settings from scratch, it may be best to start with this step ( deleting Darkmod.cfg )
before tinkering with any other setting changes. ( Especially if you haven't done this for a few upgrade cycles. )

Newer TDM versions keep your keybindings and controller settings in a separate file ( DarkmodKeybinds.cfg ) so you will just need to change
resolution, brightness \ gamma, and other graphic quality settings in addition to game-play difficulty settings.

Mission Updates

Mission authors often discover performance problems after they release their missions.
They will occasionally issue new mission versions that have improved performance.
Also, the TDM team will sometimes apply fixes to missions that can improve performance and stability in new release versions.
We recommend checking the Mission Downloader for updates to your existing missions ( denoted with an asterisk )
Note: Savegames do not work between different mission versions.

TDM performance can vary wildly depending on what any specific mission author has done to design their mission.
Before deciding that TDM is unplayable on your hardware, please try less demanding missions

Known Taxing Missions

The following are a few missions that are known to challenge low-end hardware configurations

Scroll of Remembrance
Briarwood Manor
The Rats Triumphant
Rightful Property
A Bridge Too Far

Known Low Requirement Missions

Conversely, here are a few missions that should run well on low-end hardware ( in addition to the included "official" missions )

Closemouthed Shadows
The Outpost
The Parcel
Special Delivery
The Thieves
Thief's Den 1
The Golden Skull
Langhorne Lodge
Coercion
The Bakery Job
Deadeye
A Night Of Loot: One Man's Treasure
Down and Out on Newford Road
A Matter of Hours
Sir Talbot's Collatoral

Missions that require 64-bit

Some very large missions will not load when running 32-bit TDM versions on Windows ( or may have anomalies on 32-bit Linux )
They simply cause TDM to exceed the Windows "2GB allocation limit" for 32-bit during loading.

The Painter's Wife
Penny Dreadful 3: Erasing the Trail
Shadows of Northdale ACT 1

( Note: You may be able to use image_downSize cvars to lower resources to load these missions on 32-bit Windows. )
( Note: 32-bit TDM is unsupported as of TDM 2.10. We still provide binaries but no assurance that they will work with all missions and OS versions. )

Optimizing the OS performance

Windows or Linux ?

Historically, TDM had significantly better performance on Windows because Doom 3 had no SIMD optimizations under Linux.
As of 2.06 (and newer) TDM has both SSE SIMD and AVX optimizations under both Windows and Linux
so TDM can now run faster under Linux due to less OS overhead.

Unfortunately, the default "capped FPS mode" has never worked well under Linux (even in vanilla Doom 3) so out-of-box Linux still performs worse.
Hence we advise switching to the new uncapped mode under Linux.

If you have a weaker CPU and can install Linux ( or dual boot, etc ) you may see 5 to 10% performance uplift when configured properly

Drivers

Ensure that all hardware drivers are installed and up-to-date. See "Hardware considerations" and "Linux Secure Boot" for further details.

All OS Variants: File Permissions

Make sure your darkmod folder is located in a non-protected location.

On Windows, "Program Files" is protected and will cause problems saving any settings or installing Fan Missions.

On Linux, you should consider creating your darkmod directory under your /home/<username>/ folder to avoid permission issues.

Stop running programs in the background

Programs running in the background might either eat up memory that is needed for ~~Doom 3~~ The Dark Mod,
and thus cause swapping to the hard disk, or they might consume CPU time or other resources.

This can cause either general slowdowns or hickups during game play.

Ensure that Programs are the main priority in the OS

To begin the process, type sysdm.cpl in Run box (Windows + R) and hit Enter to open the System Properties.

Select the Advanced tab and under Performance, click on Settings.

In the Performance Options box, select the Advanced Tab again.

You will see a section Processor Scheduling

Choose "Programs" then click Apply.

Disable Desktop Effects

(If you are willing to sacrifice you desktop visual behavior and effects for better TDM performance. Note: This can be reverted.)

To begin the process, type sysdm.cpl in Run box (Windows + R) and hit Enter to open the System Properties.

Select the Advanced tab and under Performance, click on Settings.

In the Performance Options box, select the Visual Effects tab.

Check "Adjust for Best Performance" then click Apply.

White-list TheDarkMod.exe in Security Software

Make sure that Windows Defender or Anti-Virus, Anti-Spyware, etc aren't constantly scanning or interacting

with TheDarkModx64.exe. Add it to your security white-list.

Windows 10 Granular Security Options

With new attacks like Meltdown and Spectre, Windows 10 has added CPU architecture specific security fixes.
Many of these have performance impacts. The impact is mostly on Storage access so loading times would
normally be the only casualty of these changes. Still, it's possible that these protections might interfere
with The Dark Mod in other ways.

Please review:

https://learn.microsoft.com/en-us/microsoft-365/security/defender-endpoint/exploit-protection-reference?view=o365-worldwide

and disable the security options you feel are excessive.

BIOS Mitigations

The Core Isolation vulnerability configuration ( see above ) is known to cause at least 10% FPS loss
Rather than safelisting TDM, if you do not use virtualization features you can disable virtualization in BIOS

Likewise, if you have 4 or more physical CPU cores, you can disable Hyperthreading in BIOS to avoid performance loss
due to many Spectre \ Meltdown mitigations

Disabling features in BIOS is the safest way to improve performance issues related to known CPU hardware exploits
Also, some vulnerabilities can be patched via a BIOS Upgrade

Disable TDM Connectivity

If you decide to bypass / safelist TDM in security software, you can mitigate risks posed by TDM's network connection by setting:


seta tdm_allow_http_access "0"

in Darkmod.cfg to block connectivity.

This comes with the caveat that the in-game mission downloader won't work, you'll need to download missions from https://www.thedarkmod.com/missions
and copying them to your darkmod/fms folder. Unless you know that your TDM executable was at risk for being replaced by a malicious version,
leaving connectivity open on it "while safelisted" is very low risk. You can further mitigate the risk by compiling your own executable.

Priority and Affinity (Advanced)

The following sub-section is a deep dive into forcing your Operating System to treat TDM as the most important application.

A well behaved and maintained OS generally will not need to be configured like this so please consider these options
to be an extreme last resort to ensure that no OS performance factors are slowing down TDM
Before applying any of these changes, ensure that you have tuned other CPU related settings in TDM

Windows Priority and Affinity

Note: As of The Dark Mod 2.08 Frontend Acceleration, defaults to 2 threads. When configuring affinity you should
ensure that at least 2 cores ( preferably 3 ) are allocated to TDM. If you increase the jobs_numThreads value
you should correspondingly increase the number of cores available in process affinity.

Set TheDarkMod to High Priority

Launch TheDarkMod

(Note: Do not start a mission or test map yet. If the 3D render is initialized it will take a long time to exit fullscreen and return to it.)

Alt + Enter to exit fullscreen
Ctrl + Alt + Del to open your Task Manager
Right-click on TheDarkMod.exe the choose "Go to Details"
(On the details\processes pane) Right-click on TheDarkMod.exe and mouse-over Set Priority and choose High
Alt + Enter to return to fullscreen

You can also edit your Desktop shortcut to start in High priority:

Right-click your Desktop shortcut to TheDarkMod and select Properties
On the Shortcut Tab enter the following into the "Target:" field


cmd.exe /c start "TheDarkMod" /High "C:\darkmod\TheDarkModx64.exe"

(Assuming you installed into C:\darkmod)

Then click the Change Icon button and browse for the Darkmod.ico icon in your darkmod install path
Click Apply

Set TheDarkMod Affinity

If you have a limited number of cores or heavy background tasks are always consuming the default cores,
you can set The Dark Mod to run on a specific core via "affinity"

Launch TheDarkMod
Alt + Enter to exit fullscreen

(Note: Do not start a mission or test map yet. If the 3D render is initialized it will take a long time to exit fullscreen and return to it.)

Ctrl + Alt + Del to open your Task Manager
Click the Performance Tab and look at the CPU display to see which cores are the least busy
(On Windows 10, click the "Open Resource Monitor" link and then click the CPU tab and expand the right pane)
Close the Resource Monitor and click the Processes Tab in Task Manager
Right-click on TheDarkMod.exe the choose "Go to Details"
(On the details\processes pane) Right-click on TheDarkMod.exe
Mouse-over then click "Set Affinity" and uncheck cores you want to prevent TDM from using
Alt + Enter to return to fullscreen

As with Priority you can set Affinity in your shortcut.

Example Target:


cmd.exe /c start "TheDarkMod" /affinity 1 "C:\darkmod\TheDarkModx64.exe"

The affinity number is not matched to the number in your performance screen.
For example "Core 0" in Task Manager is affinity 1.
The values are in Hex but are converted from binary where 1 represents an active core and 0 is disabled.
They are in a descending order.

For example: Binary 1110 means Core 3, 2, and 1 are enabled while Core 0 is disabled.
Converting from Binary to Hex gives you /affinty E. This is a useful config if the majority
of your processes are running on Core 0. FE for an 8 core chip would accomplish the same result.

Another useful option is 0101 /affinity 5 which will select core 0 and 2 which are "real" cores
in a Hyperthreading environment.

Core 0 is 1
Core 1 is 2
Core 2 is 4
Core 3 is 8
Core 4 is 10
Core 5 is 20
Core 6 is 40
Core 7 is 80
Core 8 is 100
Core 9 is 200
Core 10 is 400
Core 11 is 800

Again, the core number does not exclude hyperthread cores so if you have an 8 Core \ 16 thread CPU
you must count all real and hyperthread virtual cores when setting affinity.

Windows Combined Example

You can include both priority and affinity switches in your shortcut


C:\Windows\System32\cmd.exe /c start "TheDarkMod" /High /affinity 5 "C:\darkmod\TheDarkModx64.exe" +set r_softShadowsRadius 2.5 +r_useEntityCulling 1

Start TheDarkMod with high priority on Cores 0 and 2 (real cores) and add two launch cvars ( See Conventions ).

As you can see, you can make a huge launch string but once you go past 2 or 3 cvars it's best to

use Darkmod.cfg unless you wish to make multiple launchers for testing (etc).

Process Management Note

You can also either "End Task" on processes that you know you don't need or set them to "below normal" or "low" priority.

Moving these low priority processes to a different core via affinity is also an option.

Some processes, such as OneDrive.exe (which is integrated into the OS) will keep restarting so it's best to set these to "low priority"

If you are unsure what a process does, do not change it until you've researched the process.

Linux Priority and Affinity

Note: Linux generally does a good job of ensuring that other applications or processes are not impacting
game performance ( or really any foreground application performance ).
Managing affinity and\or priority usually has little to no effect in Linux unless you knowingly have lots of other heavy applications running.
Finally, some Linux distros are starting to ship with an enhancement package "Game Mode" that automatically prioritizes gaming

Linux Priority

NOTE: Some modern Linux distros that use pipewire audio will not render audio if
the initial command that invokes the application is run as root or sudo. I am currently investigating a workaround.

You can launch TDM with a very high priority via the "nice" command:

sudo nice --18 su -c /home/user/darkmod/thedarkmod.x64 username

There are two dashes in the above command. The first dash just tells the command that we are passing a parameter,
the second dash indicates a "negative priority number". Confusingly, the larger the negative number the higher
the priority with a maximum value of -20. Conversely the higher the positive integer, the lower the program priority!
For the sake of responsiveness, it is probably best to avoid the top or bottom if the priority range.
Also, note that the command must run as sudo to use negative priority and it's best to use "su -c program username"
so that it is run as "you" (replace username with your username) rather than root so you don't end up with root owned files.
See the visudo change in Linux Combined Example for details on how to run as sudo without a password

Example to launch with lower priority ( lowest possible value 19 ):

nice -10 /home/user/darkmod/thedarkmod.x64

You can also change the priority of TDM while it is running via "renice" and "pidof"

renice -n --18 -p $(pidof thedarkmod.x64)

Linux Affinity

Modern Linux operating systems will list cores with a list starting with 0, so ( for example ) the top core number in an 8 core CPU will be 7.

You can identify cores and whether the cores are hyperthread ( HT ) cores via:

lscpu -e

Example:

    CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ    MINMHZ
    0   0    0      0    0:0:0:0       yes    4100.0000 400.0000
    1   0    0      1    1:1:1:0       yes    4100.0000 400.0000
    2   0    0      2    2:2:2:0       yes    4100.0000 400.0000
    3   0    0      3    3:3:3:0       yes    4100.0000 400.0000
    4   0    0      0    0:0:0:0       yes    4100.0000 400.0000
    5   0    0      1    1:1:1:0       yes    4100.0000 400.0000
    6   0    0      2    2:2:2:0       yes    4100.0000 400.0000
    7   0    0      3    3:3:3:0       yes    4100.0000 400.0000

The CPU number above is what the OS recognizes when using affinity commands, the core number is actual core number.
So in the above results, CPU's 4 to 7 are hyperthreading cores whereas cores 0 to 3 are real cores.

To pin TDM to specific cores, you can change the launch options to:

taskset -c 1,2,3 /path/to/thedarkmod.x64

The above example forces TDM to run on real cores 1, 2, and 3. You may use a dash to specify a range of cores (1-3)
or even mix both syntax forms ( 1-3,6 ).

You can also change the core of a running TDM instance by using pidof to auto-locate the PID of the running process:

taskset -cp 1,2,3 $(pidof thedarkmod.x64)

More advanced users may wish to "cpuset" to create a new logical group of cores and caches (etc) then assign TDM
to run under the new CPU Set

And (of course) you can instead use taskset to move other non-critical processes to other cores or HT cores.

Linux Combined Example

NOTE: Some modern Linux distros that use pipewire audio will not render audio if the initial command that invokes the application is run as root or sudo. I am currently investigating a workaround.

In Linux nice and taskset cannot be invoked at the same time to launch an application.
You can launch TDM and use taskset to change the running process and likewise use renice to change priority
To launch with both priority and affinity at once, you can use "schedtool"
You will first need to use visudo to allow schedtool to run in sudo without a password
visudo will open an editor where you may add the following to the bottom of the file


%sudo ALL = ( ALL ) NOPASSWD: /usr/bin/schedtool,/usr/bin/nice

Then simply edit the "command field" for the properties page of your Darkmod launcher icon as follows:


sudo schedtool -R -p 50 -a 1,2,3,5,6,7 -e nice --17 su -c "/home/user/darkmod/thedarkmod.x64 +set r_shadows 1 +r_ssao 0" username

In the above example, priority (-p ) is set to -50 ( highest is -99 aka realtime ) and affinity ( -a ) is set to use real cores 2 to 4 and corresponding HT cores ).
Setting any application to -99 ( realtime ) priority is unsafe because it may be hard to exit or may lockup the OS trying to request resources.
schedtool has a "-n" flag for the nice value but it only supports positive nice values so we added the nice invoke after the "-e" ( execute flag ) and
made sure to su ( switch user ) to run thedarkmod.x64 as "username" ( eg whatever your username is ).
Finally, for good measure we have set shadows to stencil ( 1 ) and SSAO off ( 0 ) using standard Doom 3 style launch options for example syntax

Optimizing Dark Mod settings

The settings changes below generally can be changed independently of one another.

This means that if your want better settings in one aspect (such as AA) you can

try reducing quality or disabling another aspect (such as soft-shadows, ambient occlusion, v-sync, etc)

Reduce your resolution!

Important!

While the Screen Resolution section mostly applies to legacy displays (CRT's),

if TDM doesn't properly detect the Native Resolution of your modern display

you should still configure it before adjusting the Render Scale

Lower your Render Scale (New 2.07)

The new "Render Scale" slider in 2.07 allows you to reduce the internal resolution that TDM will render to.
Lowering this has a similar performance impact as lowering your Screen Resolution and is the preferred way to improve performance via resolution change
One additional benefit is that lowering Render Scale does not impact Menu and HUD / GUI resolution so you can set it much lower than screen resolution


seta r_fboResolution "0.85"

Note: With the r_fboResolution CVAR, you can also do the opposite...
You can also render to a higher than native resolution and the down-scaled output will look sorta like SSAA.
This is VERY expensive so we recommend going no higher than r_fboResolution 1.5.

Image Sharpening (New 2.09)

In 2.09 a new "Contrast Adaptive Sharpening" shader has been added and is enabled by default.
At the default Render Scale this simply improves the quality of textures (makes lower resolution textures less blurry).
When paired with a lower Render Scale values it can substantially reduce the blur and make the screen look almost like full resolution!


seta r_postprocess_sharpen "1"
seta r_postprocess_sharpness "0.7"

Screen Resolution

On modern LCD, OLED, or MicroLED displays we advise against changing native resolution unless you know that your monitor
has an excellent internal resolution scaler. You should instead change your Render Scale as described in the previous sub-section.
This section is more applicable to players using CRT or Plasma displays which naturally support a wide range of resolutions.
Even if you have a CRT or other legacy display tech, it may be better to change Render Scale to avoid legibility issues in Menus and HUD / GUI.

On older cards (or integrated graphics), ~~Doom 3's~~ TDM's render engine is very expensive for every per pixel drawn, and reducing the resolution will help the most.
For instance, at 1600x1200 the game needs to draw four times as many pixels as when running 800x600.
The result with 800x600 will not look as bad as one might think – but the frame rate improvements might make it much more playable.

If you cannot set the resolution you want in the Video Settings Menu then enter it in Darkmod.cfg. (As shown below)

Example cvars for a Native 1080p HD display:


 seta r_mode "-1"
 seta r_customwidth "1920"
 seta r_customheight "1080"
 seta r_aspectratio "1"

For the lowest possible resolutions, search down for these cvars first and replace them with the values shown:


 seta r_mode "-1"
 seta r_customHeight "640"
 seta r_customWidth "480"

alternate for low resolution on wide screen monitors:

16:9 ratio

seta r_mode "-1"
seta r_customwidth "1280"
seta r_customheight "720"
seta r_aspectratio "1"

See also: "Resolutions" (for a list of known configurations)

Lower Anti-aliasing

The Dark Mod ships with standard "Multi-Sample Anti-Aliasing" ( MSAA ). This can reduce or eliminate jagged pixelization on geometry edges
by sampling sub-pixels near those edges and blending based on the average color. In practice this means that every visible geometry edge will get rendered
at a multiple of it's native resolution ( depending on your setting; eg. 2x, 4x, 8x, 16x ).
While this is still lower than increasing your overall screen resolution by the same factor, it can still increase the render workload by 50% or more in dense scenes.
MSAA is particularly heavy for Stencil Shadows but 2.11+ have some dedicated optimizations to improve that.

Unfotunately, if you needs the extra performance, you may need accept some aliasing ( jaggies ) unless your GPU vendor offers better in-driver options.

Since AA approximates a higher resolution, you may prefer disabling it in favor of choosing a higher resolution ( eg 1080p with 8xAA verses 1440p with no AA )
( Depending on your graphics performance, it may be better to use a lower Render Scale and then use a higher AA value to retain clean edges. )

In the standard video settings, set AA to a lower value or 0


seta r_multiSamples "0"

in Darkmod.cfg

Note: Nvidia's in-driver FXAA anti-aliasing setting is substantially faster than the multi-samples settings in game.
( Warning: FXAA can make text and GUI's a little blurrier )
Doom 3 is far less susceptible to AA artifacts so FXAA may be an acceptable alternative especially if you are are running the game at native resolution (or nearly native).
AMD has MLAA which works in a similar way.

Incidentally, if you have GPU power to spare you can either use your GPU driver settings to force even higher quality modes such as SSAA
( that performs sub-sampling to every pixel ) or configure TDM Render Scale ( r_fboResolution ) above native resolution for an SSAA effect.

Screen Refresh and FPS

In theory, screen refresh and FPS should be independent of engine and driver performance.
Unfortunately, the OS, Drivers, and OpenGL API often cause slowdown and performance issues if refresh settings are misconfigured

Uncap FPS (New in v2.06)

Run one game tick per graphics frame, rather than fixed 60 ticks per second.

In 2.06 this is now a GUI option "Uncap FPS" in the Advanced Video settings GUI menu.

This not only makes the player camera move more smoothly but can also improve performance
since some drivers do not work well with the capped FPS design.


seta com_fixedTic "1"

in Darkmod.cfg

Note: Uncapping FPS is crucial to a smooth performance in most Linux environments!.


The default capped design appears to have some flaw for frame timing against the native Linux timer

Uncapping FPS or running TDM capped under Wine will resolve this.

Native Doom 3 builds are also impacted by this problem so it predates The Dark Mod. 

The Dark Mod cannot use com_preciseTic 0 as a workaround ( some users have used this to improve Linux Doom 3 frame timing )

Uncapped mode has the additional benefit of making video playback properly sync to audio.

The Dark Mod team has worked hard to ensure that the uncapped mode is bug free at high FPS values but if you wish to

reduce the risk of high-FPS related bugs, set your Max FPS ( com_maxFPS, see below section ) to 75 or less.

Max FPS (New in 2.08 )

In 2.08 you can define the max FPS via the Max FPS setting in the Advanced Video settings GUI menu.
(This is setting is meant to be paired with th Uncapped FPS mode above.)


seta com_maxFPS "90"

in Darkmod.cfg

Run The Dark Mod in fullscreen

Running Darkmod in windowed mode might be quite a bit slower than fullscreen mode.

One reason for this is that windowed mode is sometimes forced to V-sync. ( See Disable V-sync )

seta r_fullscreen "1"

in Darkmod.cfg

In 2.08 you can choose between Windowed, Fullscreen, and Borderless Windowed. Fullscreen is the lowest latency option.

Fullscreen Windowed in Modern Windows Versions

It has become widely recognized that v-sync is a source of input delay and forcing it for both Windowed and Fullscreen Windowed modes
is not optimal. The latest Windows versions no longer force v-sync on Fullscreen Windowed applications but if you encounter any issues
or have an older Windows release you should be able to force it off via your driver application profile settings:

If you have a Nvidia card

Open Windows start menu and type: Nvidia control panel
Click Manage 3D settings, on the left pan
Under "I would like to use the following 3D settings" scroll down until you see "Vertical sync."
Select Vertical sync choose "Force off" or " disable" ... from the drop down.

For AMD

Click the Start button or Windows icon.
Type "Catalyst control center" in the search bar.
Press Enter on your keyboard.
Click Gaming.
Under "3D Application Settings" scroll down to "Wait for vertical refresh."
Move the slider down to the side that says "Performance" so the text beneath it says Always Off.

The above won't be necessary for users with variable refresh displays and video cards with variable refresh support such as G-Sync or Freesync.

Force Refresh Timing

(Related to vsync)

Some newer video cards may not properly report the refresh rate to this engine (typically digital output like DVI, HDMI, or DisplayPort)
This can cause lag, stutter, and uneven frame pacing.

Create an autoexec.cfg in your darkmod directory and set:


seta r_displayRefresh "60"

(Obviously increase to match your available mode.)

Disable V-sync

Depending on your drivers and driver settings, Vsync will cap FPS to the closest available standard refresh rate.
This means that if your FPS go below 60, TDM may be capped at the next standard value of 30FPS rather than
rendering at 40FPS or higher which would feel smoother.
Further, sometimes capping FPS will prevent TDM from recovering from a lower FPS in a timely manner.

Unless you are extremely sensitive to screen-tearing, we advise that you disable vsync
(If your GPU driver supports variable refresh tech such as Freesync or G-sync, it may be preferable to force that feature via a Driver Profile)

In the standard video settings, disable vsync

seta r_swapInterval "0"

in Darkmod.cfg

New Info: Setting r_swapInterval "-1" enables "Adaptive Vsync" which only performs the sync action when you are at or above refresh rate.
This has much less performance impact.

NEWER INFO TDM 2.10 has an Adaptive Vsync option in the Video Settings GUI

Multi-Core Options

Starting with TDM 2.06, there has been an ongoing effort to improve the TDM Engine to take advantage of Multi-Core CPU's
If your CPU has more than 1 core (or offers Hyperthreading), the following settings can dramatically improve performance

Enable Multi-Core (new in v2.06)

In 2.06 the engine splits the Frontend and Backend into separate threads if you enable the Experimental "Multi-Core" setting
in the Advanced Video settings GUI menu.


seta com_smp "1"

in Darkmod.cfg

In 2.09 this is enabled by default. The setting is no longer in the GUI.

Frontend Acceleration (new in v2.09+)

In 2.09 the engine frontend can submit models to the render backend via parallel jobs on multiple CPU cores.
This is similar to how Doom 3 BFG handles rendering.
Enable "Frontend Accelleration" in the Advanced Video settings GUI menu.


seta r_useParallelAddModels "1"

In TDM 2.11 this is enabled by default.

Jobs Settings

Also, you can increase the number of assigned cores:


seta jobs_numThreads "3"

( See the Affinity section regarding OS CPU Core management in relation to these options. )

Shadow Settings

Change Shadow Mode (New 2.07)

In TDM 2.07+ we offer two different "Shadow Implementation" options in the Advanced Video Settings GUI.

Maps (Shadow Maps)

Stencil (Stencil Shadow Volumes)

( There is a 3rd mode "No Shadows" It's available via the console and can be used for troubleshooting.
Some missions might be playable in this mode but will probably be very difficult with no shadows to hide in.
Darkness can still exist in areas outside the light radius or falloff though. )

Shadow Maps can perform better in scenes with fewer but larger light sources and less small shadow casters.
Shadow Map performance depends on the amount and speed of VRAM on you GPU
Most of the calculations are done on the GPU in this mode so if you have a weak CPU and mid-range GPU ( usually old desktops )
this mode is preferred

Stationary Lights + Big areas + Big Lights = Higher FPS with Maps

Stencil can perform faster for systems with powerful CPU's and weak GPU's ( usually laptops ) because it mostly relies on fillrate.
Stencil soft shadows sometimes run faster because they don't do calculations for "distance to blocker" ( contact hardening )

Lots of small moving lights + confined spaces = Higher FPS with Stencil

Maps mode:


seta r_shadows "2"

Stencil mode:


seta r_shadows "1"

in Darkmod.cfg

(If you change this via the console, also invoke shadowimplchanged or you may be missing some shadows)

Lower or Disable Soft Shadows (New in v2.06)

Shadow Quality determines how many gradients ( color bands) that soft shadows use.
In the advanced videos settings menu set the Soft Shadows quality slider to low or off


seta r_softShadowsQuality = 0

in Darkmod.cfg

Softening Radius

In the advanced videos settings menu set the Shadow Softness slider to make shadows softer without increasing the quality level


seta r_softShadowsRadius 2.0

in Darkmod.cfg

You can experiment with values between 1.5 and 3.5 or more.
Another way to get blurrier shadows without "cranking the quality" is to use Shadow Maps and set a very low Shadow Map Size

Soft Shadows Mipmaps ( New in 2.11 )

To reduce the impact of sampling shadows for soft shadow effects and MSAA ( in Stencil mode ), 2.11 introduced a new mipmap optimization


     seta r_softShadowsMipmaps "1"

in Darkmod.cfg ( default setting, no change should be needed )

Shadow Map Settings

Shadow Maps require more complex designs to optimize texture usage and reduce \ avoid artifacts.
Correspondingly, TDM has many settings specific to this mode

Single Pass Shadow Maps

Rather than calculating all shadows one-at-a-time, all shadow casting is calculated in one pass for every light in the scene.
THIS CAN OFFER SUBSTANTIAL PERFORMANCE IMPROVEMENT


seta "r_shadowMapSinglePass "1"

in Darkmod.cfg

~~2.10 Issues:~~

~~The old backend does not work with this mode ( r_useNewBackend 0 )~~

~~For some users, screenshots will be missing shadows for func_static geometry if this is enabled~~
The screen-shot issue is resolved in 2.11+

NEW - All known issues for this mode are fixed. This is enabled by default in 2.12

Shadow Map Size

The larger the Shadow Map texture, the more detail and less artifacts you have further away from the light center or for small objects.
Conversely, smaller Shadow Map textures perform much better (use less resources).
Since stretching a low resolution shadow texture over a large area naturally causes bi-linear blurring,
some players prefer lower resolution maps instead of increasing the quality and softening radius which produces less blur
(due to realistic contact hardening simulation in the light shaders).


seta r_shadowMapSize "384"

You can also increase this to reduce light leaks from the experimental Front Culling Optimization.
On balance enabling Front Culling may offset the performance pitfalls of a bigger shadow map.
You can experiment with shadow map sizes that are slightly larger than 1024 such as 1280 or 1440.

This setting can also be used to reduce the performance impact of Volumetric Lights because they
always use Shadow Maps regardless of Shadow Mode
If your GPU runs missions without Volumetric Lights well in Stencil Mode but struggles with missions that contain them,
try setting the map size to 256 or lower.

Max Light Size

The larger the light, the more Shadow Map resolution you need (see Shadow Map Size ).
There are some lights so large that Shadow Maps will never look good without insane texture sizes.
You can set a threshold to say if lights are bigger than X, use Stencil Shadows.


seta r_maxShadowMapLight "1500"

Lower or Disable Ambient Occlusion (New in 2.08)

In the advanced video settings menu make sure that Ambient Occlusion is set to low or off.


seta r_ssao "1"

or


seta r_ssao "0"

in Darkmod.cfg

SSAO Radius

You can widen the SSAO radius to improve the appearance or shrink it to improve performance


seta r_ssao_radius "24"

Reduce Color Depth (New in 2.08)

In TDM 2.08 the default Frame Buffer was upgraded to use 64-bit color to reduce color banding.
Some GPU's have poor support for this format or render much slower. Consider reverting to 32-bit.
Change Color to 32-bit under the Advanced Video settings menu or:


seta r_fboColorBits "32"

in Darkmod.cfg

Disable Bloom

In the advanced video settings menu make sure Bloom is disabled


seta r_bloom "0"

in Darkmod.cfg

TDM versions older than 2.08

Disable Postprocess in the GUI or set:


seta r_postprocess "0"

in Darkmod.cfg

Set Object Detail to Low

In the advanced video settings menu lower the Object detail slider below normal

seta tdm_lod_bias "0.5"

in Darkmod.cfg (see also Object Detail )

Field of View Decrease

Motion Sickness Warning

FOV adjustment is mostly for player comfort and to reduce motion sickness.

Lower FOV values are more inclined to cause motion sickness.

16:9 players can lower to FOV 75 to eliminate foveal edge distortion but doing so increases the risk of experiencing discomfort
(The default FOV ( 90 ) for TDM was design for 4:3 ratio screens.)

You can get a performance improvement if you decrease the field of view. By default this is 90 degrees but you might try entering in the console:

g_fov 85

or

seta g_fov "85"

in Darkmod.cfg

In addition, if you are playing a mission that is too good to miss and reach a very low performance area which is almost unplayable on your machine,
you might consider setting the field of view extremely low temporarily to get you through then restore to 90 later...

g_fov 50

or bind a toggle

bind "z" "toggle g_fov 50 90";

in DarkmodKeybinds.cfg so you can tap a key to go between FOV ranges.

See Toggle Settings in Realtime

Note from Fidcal: I have played comfortably on g_fov 75 and even think perhaps it makes nearby objects more realistically close so you can get right up to a table, etc.
Not noticed any problem with restricted view.

Note: On older TDM releases some players reported that changing this setting might occasionally produce odd effects such as a grabbed object seems to move a little on release.

Lower Anisotropic Filtering ( Not recommended )

In the standard video settings, lower or disable Anisotropic Filtering ( AF )


seta image_anisotropy "0"

in Darkmod.cfg

Note: This has very little performance benefit for most GPU hardware. The mipmaps needed to perform AF are already loaded into
VRAM so the only savings are very inexpensive sampling operations that are normally handled by dedicated filtering hardware.

In 2.09 if you change Anisotropic Filtering and have "r_useBindlessTextures 1" set (default) the game may stutter
when you return from the menu because it must rebuild all the textures.
To avoid this, set "r_useBindlessTextures 0" then restart the game and test your preferred AF mode then once you have found your
performace-to-image quality sweet spot set "r_useBindlessTextures 1" and restart TDM

NEW: In 2.11+, bindless texture support was removed due to multiple issues with AMD drivers.
You should be able to change anisotropic filtering settings in the GUI without encountering stutters.

OBSOLETE Set the ambient shading to "Faster"

Inside the settings, change the ambient rendering method to "Faster".

~~seta tdm_ambient_method "1"~~

in Darkmod.cfg

(Note: Some preliminary tests in v2.05 show that the Enhanced Ambient is now faster than the "fast" texture based Ambient.)
(Note: This setting has been removed in 2.09+ )

OBSOLETE Set the interaction.vfp to "Standard"

In the video settings menu, change the interaction shader to Standard. Lighting will not look as good, but you may gain a few frames per second.

~~seta tdm_interaction_vfp_type "0"~~

in Darkmod.cfg

In 2.08 this setting is


seta r_interactionProgram "0"

This setting doesn't work in 2.09+ It is a stub cvar that does nothing.
If you wish to test interaction shaders, create a glprogs folder in your mission folder with new shaders having the same name as the default ones.
You can keep the default shaders in the same folder in renamed form then swap filenames and execute reloadGLSLprograms to compare changes.
For a more clean comparison also set g_stopTime to prevent dynamic light changes

Slow loading times

OBSOLETE! TDM 2.10 has very fast loading times!
The only setting that might improve loading times is "seta image_preload 0"

If you find an FM is very slow to load it may be an ATI graphics card problem.
One report says this was cured by turning off Catalyst AI. Also cures HDR-Lite Post-Processing Problems.

Changing the following settings to 0 will also reduce loading time, but be warned:
if you have a lower-end system, poor graphics card, or low ram,
you will likely notice a performance hit in-game since you will now be using uncompressed textures.

~~seta image_useNormalCompression "0" seta image_useCompression "0" seta image_preload "0"~~

New 2.10+ cvars ( defaults ) for fast loading times:

 seta image_levelLoadParallel "1"
 seta image_useTexStorage "1"
 seta image_mipmapMode "0"

In 2.10 the RXGB normal map compression format has been replaced the higher quality RGTC format.

Note: Disabling compression is not recommended and may lead to Malloc errors due to heavy memory consumption.

If you want to disable compression, you may be able to compensate by setting Image Downsizing settings.

The game is very slow!

Important!

If you do not have properly installed hardware drivers, TDM may be rendering graphic features using your CPU
or may be performing CPU tasks in legacy modes. THESE ARE INCREDIBLY SLOW. See Hardware Considerations

Likewise, Linux players will need to either have a Signed Kernel ( and Drivers ) or disable Secure Boot since unsigned hardware lacks acceleration
Linux players will also need to ensure that TDM is in "Uncapped FPS mode" or they will have performance problems regardless of their hardware capabilities.

Finally, if you have a laptop with 2 GPU options it can also behave as if you don't have hardware acceleration when using the weaker GPU.

Defaults

The advised performance defaults below should mostly already be set by default on upgrade.

Please consider deleting darkmod.cfg after upgrading to restore these defaults.

If you get less than 10 FPS, or the game even stutters, please try this:

Look into your Darkmod.cfg inside your darkmod folder and check that the following settings are like shown below:

 seta image_usePrecompressedTextures "1"
 seta image_useNormalCompression "1"
 seta image_useAllFormats "1"
 seta image_useCompression "1"
 seta image_preload "1"
 seta r_useCachedDynamicModels "1"
 seta r_useShadowVertexProgram "1"
 seta r_useEntityCulling "1"

Note: r_useShadowVertexProgram no longer exists in TDM. All shadow modes use GPU vertex operations.

OBSOLETE 2.09 performance defaults

 seta r_useMultiDrawIndirect "1"
 seta r_useBindlessTextures "1"

2.11 new performance defaults ( in addition to the standard performance defaults above )

 seta r_useNewBackend "1"
 seta r_modelBvhBuild "1"
 seta com_smp "1"
 seta r_useParallelAddModels "1"
 seta r_usePersistentMapping "1"
 seta com_useMinorTics "1"
 seta com_fixedTic "1"
 seta com_maxFPS "166"

2.12 new performance defaults ( in addition to the standard performance defaults above )

 seta r_useLightPortalFlow "2"
 seta r_useLightPortalFlowCulling "1"
 seta r_softShadowsMipmaps "1"
 seta r_useEntityScissors "1" 
 seta r_animationBounds "1"
 seta r_useNewRenderPasses "1"
 seta r_shadowMapSinglePass "1"

Note: 2.12 r_useNewRenderPasses replaces r_useNewBackend

Frame Memory

New in TDM 2.08

r_frameIndexMemory

and

r_frameVertexMemory

Increasing frame memory may help avoid crashing or slow-down when a scene suddenly requires more resources.
If you are VRAM limited, consider lowering texture quality ( Image Downsize ) or Render Scale before increasing these.

Disabling standard graphics features

At the cost of some pretty severe scene quality, you can disable a number of independent graphic features

that are non-essential to play.

Texture Based Tweaks

These changes reduce or remove texture data to improve performance on GPU's with low VRAM or low memory bandwidth

Image downsizing

TDM can automatically reduce texture resolution for all 3 supported texture types; diffuse,
normal (bump), and specular. Systems with very low quantities of VRAM or low memory bandwidth benefit from this change.
Note: You must restart TDM or invoke reloadImages for image_downsize settings to take effect

In Darkmod.cfg, set image_downSize to 1 and then set a limit with image_downSizeLimit, e.g., "image_downSizeLimit" "256".


seta image_downSize "1"
seta image_downSizeLimit "256"

This reduces texture memory requirements and may completely alleviate hard drive thrashing for dynamic image loading.
Try lowering to 512 and if you still need more VRAM or need lower RAM usage during mission load ( see 64-bit missions ) then move down to 256, 128, or 64

There are similar cvars for bump and specular maps as well.

Example: Downsize Normal Maps


seta image_downSizeBump "1"
seta image_downSizeBumpLimit "256"

Example: Downsize Specular maps


seta image_downSizeSpecular "1"
seta image_downSizeSpecularLimit "64"

Many players have found that they prefer lower resolution normal maps rather than low resolution textures

Image Downsizing verses Lower Resolution

Higher resolutions require larger frame buffers thus more VRAM, likewise higher resolution textures also consume VRAM
This leads to the an interesting decision on visual tradeoffs.

When you lower the resolution substantially, the overall visuals of the scene are roughly preserved in general way
but the scene becomes sort of impressionistic, filled with artifacts, and somewhat hard to read

When you instead lower texture resolution to the extreme (lower than 128), the scene remains sharp but takes on a more stylized \ cartoon aspect
because all these high fidelity 3D objects are coated in blurry images. It makes TDM look like a beefed-up Nintendo 64 game.
If you set image filtering to Nearest mode, TDM instead looks like a strange offset of Minecraft

In this case, there is no objective winner.

Some people actually prefer the low-texture options to the native presentation due to the interesting style or nostalgic appearance.
Whereas others will consider the extreme style variance to violate the immersion of the scene and would prefer to suffer with less
scene fidelity for the sake of cohesion.

Thread:

https://forums.thedarkmod.com/index.php?/topic/19498-image_downsize-in-206/

Disable Specular Maps

Specular gives materials their shine. This option will make all surfaces shine-free.

Note: This may not work with the Enhanced Ambient


seta r_skipSpecular "1"

in Darkmod.cfg

Disable Normal Maps

The main detail attribute for textures in Doom 3 \ Darkmod is the Normal Map.

If you disable this your game will become really ugly.


seta r_skipBump "1"

in Darkmod.cfg

Disable all Ambient Surfaces

Related to skipping particles, r_skipAmbient will get rid of any non-lit* particles
(*most particles are additive blends and don't react to light)
along with any other surfaces that don't change based on illumination (most decals, additive glowing windows, etc.).


seta r_skipAmbient "1"

in Darkmod.cfg

Light and Fog tweaks

These tweaks reduce or eliminate the impact of fogs and volumetric light effects which are often heavier than normal lights.

Disable Volumetric Lights (New in v2.11)

Volumetric lights force shadow map rendering for their light radius ( per light ).
If you have a GPU with low VRAM or poor VRAM bandwidth ( less than 128-bit bus, integrated graphics, etc),
it may be worthwhile to disable them or reduce your default shadow map resolution ( r_shadowMapSize ).

To disable volumetrics entirely, set:


seta r_volumetricEnable "0"

in Darkmod.cfg

Disable Volumetric Shadows

Volumetric Lights force expensive Shadow Maps in Stencil Mode. You can disable that via


seta r_volumetricForceShadowMaps "0"

in Darkmod.cfg

Lower Volumetric Samples

The more samples the smoother the volumetric lights at the cost of lots of performance.
Try lowering the samples. Also try changing the r_volumetricBlur and r_volumetricDither values.


seta r_volumetricSamples "16"

in Darkmod.cfg

Disable BlendLights


seta r_skipBlendLights "1"

in Darkmod.cfg

Disable Fog


seta r_skipFogLights "2"

in Darkmod.cfg

As of 2.08 and newer there are several modes of fog disable behavior. Mode 1 only disables it for opaque objects (etc)

Particle Tweaks

Particles mostly impact CPU performance but can impact the GPU due to lots of alpha operations and overdraw

Disable Soft Particles ( New in 2.03 )

The new Soft Particle effects in v2.03+ use a little more GPU than the previous particles.

This is offset by the fact that v2.03+ doesn't render particles during the lightgem calculation.

Still, if you want an extra boost then set:


seta r_useSoftParticles "0"

in Darkmod.cfg

Disable Particles ( Not recommended )

This will seriously mar your image quality. Flames, glares, and smoke will all be gone.


seta r_skipParticles "1"

in Darkmod.cfg .

Entity Shadow Tweaks

Disable Player Shadow

The player shadow slightly reduces performance. It has no game effect at all (not seen by AI for instance) apart from atmospheric effect so if you want to disable it enter in the console:

g_showplayershadow 0

Or, in Darkmod.cfg (see above) change the following line from "1" to "0":

seta g_showplayershadow "0"

This is the default setting as of TDM 1.02 and newer.

Disable Player Lantern Shadow

You may notice a drop in performance while using the player lantern.

Add "noshadows" "1" to entitydef light_lantern_moving in tdm_playertools_lantern.def and this stops the player lantern casting shadows.
This helps improve performance slightly when using the lantern.

Disable Sky

(New in v2.05) Pitch black sky with no clouds, Moon, or stars


seta g_enablePortalSky "0"

in Darkmod.cfg

Disable Lip Sync

AI will not play lipsync animations


seta tdm_ai_opt_nolipsync "1"

in Darkmod.cfg

OBSOLETE Drop in Frame Rates when Viewing Water

Some players have reported a drastic drop in performance when an agitated water surface is in view. (This on a Radeon card.)
Try entering this in the console. It disables the water visible surface effects but at least it might let you play normally...


 seta r_skipPostProcess "1"

or

~~seta r_postprocess "0"~~


seta r_bloom "0"

You can also set a key-bind to toggle this instead:


bind "z" "toggle r_bloom 0 1"

See Toggle Settings in Realtime

See also Underwater performance poor

TDM 2.12 has improved underwater performance. It no longer uses the postprocess pipeline.

Gameplay Performance Tips

If you have done everything else you can and performance is still poor then one or two things you might do in game to help:

Close all doors after you have passed through. Generally the game has to process both areas until you close the door if the doorway is still in sight.
Kill or KO every AI you can. You might not like to play that way but generally, AI still hog resources even out of sight (depending on how set up in the game.)
Avoid alerts. A dozen guards searching for you will really slow things down on a low-end machine.
Try to look down at the ground when moving along. Gazing up at a grand vista will slow you down. Best to do your gazing while standing still.

Revert to 2.03 AI Search behavior

The new AI "hiding spot" routines in 2.04 (and newer) are more CPU intensive than 2.03's search method. Try the old 2.03 mode.

 
seta tdm_ai_search_type "1"

in Darkmod.cfg

Lightgem Calculation Optimizations

The Lightgem used to be a very taxing calculation because it required the entire scene to be rendered to an off-screen
image that was then slowly passed to parser code to comb all pixels for the brightest value.

As of TDM 2.05 and newer, only shadow casting geometry is rendered during the Lightgem calculation and the
pixels are read directly from an "OpenGL Buffer Object" at high speed.

Further optimizations after 2.05 include:

Moving the calculation to it's own Thread and utilizing SMP
Making the calculation part of the native Doom 3 sub-view system
Excluding Lightgem calculations from many phases of the render system that are not applicable
Inheriting optimizations from the overall renderer ( Improving TDM render speeds, improves the Lightgem render speed )

This means that the old configurations to reduce the impact of Lightgem calculation are mostly irrelevant
except for niche scenarios (such as 120FPS+ gaming), very old hardware ( Single Core CPU's ), or very old TDM versions ( older than 2.07).

Lightgem interleaved calculation

By default lightgem calculation occurs every frame. You can set lightgem calculation to happen only once
per several frames by setting tdm_lg_interleave console parameter to values higher than 1.
For example, typing:

tdm_lg_interleave 3

in console tells TDM to recalculate lightgem value every third frame.

This tweak can increase average FPS, but it often produces noticeable stuttering, especially on slow machines when your FPS is below 25 to 30FPS.

Lightgem interleave minimum FPS ( New in 2.05)

In TDM 2.05 there is a new tdm_lg_interleave_min cvar that allows you to set a cutoff point for FPS below which the Lightgem Interleave optimization takes effect.
It is set to 40 by default. If your FPS goes below 40 then tdm_lg_interleave returns to the default value of 1 internally to prevent stutter.
Depending on your sensitivity you may wish to increase this to 50 or more.


tdm_lg_interleave_min 40

As the cost of lightgem calculation is (also) substantially lower in v2.05 and newer, you may be able to set this to 1 for most missions.

In testing, the only mission I found that suffered from "tdm_lg_interleave ( > 1) stuttering" was "Penny Dreadful 3: Erasing the Trail".
For that mission, I set tdm_lg_interleave_min to 50 to cure the stutter.
This setting can also be used to boost already high FPS values for the new unbounded FPS option.
(eg. If you have 90FPS set tdm_lg_interleave to 7 and tdm_lg_interleave_min to 75 to attempt a push towards 120FPS)

In 2.06 with the lightgem calculated on a different thread, this can likely stay at double your interleave value regardless of how low the FPS gets.

Weak Lightgem (Not Recommended)

Setting:


seta tdm_lg_weak "1"

in Darkmod.cfg will disable the renderer based lightgem and use a simpler math-based solution.
It's a far less accurate lightgem but may allow weaker systems to play the game as a last resort.

OBSOLETE Lightgem Split

During the initial development of TDM, it was found that you would get better frame pacing and a smoother experience
if you split the Lightgem calculation into half a run per cycle.
This was even better than interleave but could also be "used with interleave" to offer even more performance.
Unfortunately, the "split mode" caused some unwanted flicker in particle effects so it was disabled by default.
The flickering was cured in TDM 2.03 when SteveL prevented particles from rendering during the Lightgem phase
The flickering was rarely experienced even prior to 2.03 so if you are running a Doom 3 mod version
you would likely be able to enable the optimization without any issue.
In TDM 2.06, the feature was hard-coded to enabled, there is no configuration to enable \ disable it now.

For 2.05 and older set:


seta tdm_lg_split "1"

in Darkmod.cfg

Lower Sound Quality

Disable EFX reverb (new 2.06)

The new EFX audio option (equivalent to EAX) has some impact on mission performance, due to additional reverb calculation by the CPU.
Disable this option for extra performance. Especially if you get big stutter or lockup events opening doors from indoor to outdoor areas.
This option, disabled by default, is toggled with the main menu's "Audio/OpenAL EFX".

Turning on this option makes no performance or audio difference if the mapper didn't include an EFX file. For more about that, see Setting Reverb Data of Rooms (EAX).

Force 22khz

~~2.06: Do not use this optimization. It is known to cause issues with loading missions on some OpenAL hardware:~~
~~http://bugs.thedarkmod.com/view.php?id=4814~~

(This is fixed in 2.07)

You can force 22khz audio processing to reduce the CPU overhead of audio processing.

Obviously, EAX effects will increase CPU load for audio so you should consider disabling

those before lowering audio quality. If normal audio plays fine but EAX causes performace,

this change might give you a boost while EAX is enabled.


seta s_force22kHz "1"

Experimental Features

These settings may offer some performance benefits with caveats \ bugs.

Shadow Map Cull Front

The default shadow map mode calculates shadows for both polygons that are on the side facing
the light (front) and the side facing away from the light (back).
Cull Front mode improves performance by only calculating the back side shadows.
This mode is almost production ready. It actually fixes or improves some visuals that the default mode produces
but it has some glaring artifacts such as light leaks where surfaces meet in corner areas.
In most missions, you will not be able to tell the difference other than the improved performance


seta r_shadowMapCullFront "1"

Alpha Tested Shadow Maps ( New 2.12 )

Shadow Maps can cast shadows through transparent parts of textures. This is not currently possible with stencil shadows.
To enable this feature:


seta r_shadowMapsAlphaTested "1"

in Darkmod.cfg

Note: Be advised that this consumes more performance so if this is enabled then consider disabling it if you are struggling with performance

Use BFG style Portal Culling (new in v2.06)

If you have a system that works well with Multi-Core ( com_smp 1) then you may consider enabling r_useAnonReclaimer to reduce cache thrashing.

2.07 and newer


seta r_useAnonReclaimer "1"

2.06


seta r_useBfgPortalCulling "1"

in Darkmod.cfg

OBSOLETE Single Pass Light Rendering ( 2.09 )

THIS OPTION DOES NOT WORK IN 2.11

Similar to modern "Forward+" rendering, all lights and shadows are calculated beforehand and rendered in one pass.


seta r_shadowMapSinglePass "2"

in Darkmod.cfg

You have probably noticed that this uses the same CVAR that single pass shadows uses.
Single Pass lighting requires Single Pass shadows.

This mode (2) does not seem to improve FPS for some Nvidia hardware.
This is probably because of the Nvidia's tiling (deferred rendering) hardware optimizations.

OBSOLETE Skip Dynamic Shadows

This setting is no longer available as of TDM 2.12

Only render shadows from Stationary lights. This will break missions where players might need to hide in a moving shadow.


seta r_skipDynamicShadows "1"

Hardware Considerations

If you can correct hardware deficiencies you may not need to perform as many tweaks or setting changes.
Sometimes it is as simple as a Driver or BIOS update. Other times, you may need to consider updating hardware.

Driver Considerations

(IdTech4) The Dark Mod was originally based on OpenGL 2.0. (the same as Doom 3)

GPU manufacturers have largely ignored issues with this older specification so a number of workarounds have been

compiled by the community to attend to erroneous behaviors or poor performance.

As of TDM 2.06 and newer The Dark Mod uses OpenGL 3.x so many of these suggestions are no longer applicable.

That said, even OpenGL 3.2 (current requirement) is an old standard so some newer workarounds may be needed.

Linux UEFI Secure Boot

With Secure Boot enabled in the BIOS, some Linux distros will fallback to (slow) open drivers and wont have access to most hardware features.
If your Linux distro doesn't offer "Signed Kernels" and "Signed Drivers" disabling UEFI may be the only way to have acceptable performance
We recommend that you consider using a Linux distro that offers Signed Kernels such as the latest Ubuntu, OpenSUSE, Debian, Linux Mint versions

Linux Kernel Version

For AMD and Intel hardware, the drivers come with the Linux Kernel. Some Linux distros ship with older Kernels that do not support the latest hardware.
Many of these distros offer options to upgrade to newer Kernel versions with better hardware support.
Ubuntu and Linux Mint offer "OEM Signed Kernels" that offer newer hardware support and are signed so they can be used with Secure Boot.

Lower in-driver quality settings

AMD, Nvidia, and Intel all give users the option to lower texture quality and

also have various quality "optimization" levels for texture LOD Bias and Anisotropy (Filtering).

Driver Anti-Aliasing Settings

TDM ships with standard Multi-Sampling Anti-Aliasing ( MSAA ) which is more taxing on performance than some newer
Anti-Aliasing technologies.

For example, Nvidia's in-driver FXAA anti-aliasing setting is substantially faster than the multi-samples settings in game.
( Warning: FXAA can make text and GUI's a little blurrier )
Doom 3 is far less susceptible to AA artifacts so FXAA may be an acceptable alternative especially if you are are running the game at native resolution (or nearly native).
AMD has MLAA which works in a similar way.
Both AMD and Nvidia also offer AA enhancements to smooth transparent texture edges.

Incidentally, if you have GPU power to spare you can either use your GPU driver settings to force even higher quality modes such as SSAA
( that performs sub-sampling to every pixel ) or configure TDM Render Scale ( r_fboResolution ) above native resolution for an SSAA effect.

Try different driver versions

Sometimes updating to the latest driver version or reverting to an older version

will improve performance. Try a few revisions or ask about known good driver versions.

This applies to both GPU drivers and "Motherboard Chipset Drivers".

Intel ( new 2.09 )

Some Intel drivers do not perform well with persistent mapping enabled.
In 2.09 there is a special persistent mapping mode that works better for this hardware.
You must disable standard persistent mapping to use this mode.


r_gpuBufferNonpersistentUpdateMode "1"

r_usePersistentMapping 0

(AMD\ATI) Disable Catalyst AI

2018: The latest Radeon Crimson and Adrenalin Drivers:

Surface Format Optimization = OFF

Disable Catalyst AI in recent AMD Drivers

(AMD\ATI) Rename the executable

Most modern drivers have built-in profiles for the executable names of commercial games.

Renaming TheDarkMod.exe to the name of a commercial OpenGL game may gain you some optimizations

or even a Crossfire profile (I believe DarkAthena.exe had one.)

Known working renames:

DarkAthena.exe (thus far the most consistent improvement)

Doom3BFG.exe

Wolf2MP.exe

Amnesia.exe

Brink.exe

Prey.exe

(Nvidia) Optimus Laptop wont use your Nvidia GPU

(Nvidia) Disable the Streamer Service

Open your run dialog (Windows + R) or command prompt and type services.msc

On the Extended Tab locate "Nvidia Streamer Network Service"

Right-click it and choose "Stop"

Once the service is stopped, right click it again and choose Properties

On the General Tab set Startup Type = Disabled then click Apply.

Do the same for "Nvidia Streamer Service"

Do the same for "Nvidia Telemetry" service(s).

Note: There is a GUI option to disable streaming in the newest Geforce Experience settings page.

You would still be advised to disable the Telemetry service for extra performance.

You can also perform these steps for any services that you know can be manually started

or are not needed for your daily usage. (Obviously) Do not disable any service that you don't

recognize or know is safe to disable.

NEW INFO:

The Nvidia Streamer Service is now tied to the "Geforce Experience" "In-Game Overlay" setting.
Disabling that feature in Geforce Experience should accomplish the same as the above.

(Nvidia) Disable Threaded Optimizations

Open Nvidia Control Panel ->

Manage 3D Settings ->

Bottom half of list locate "Threaded Optimization" <-- Set to NO / Off

Also set "Multi-display/Mixed GPU acceleration" to "Single display performance mode"

This can also reduce or eliminate driver crashes or rendering anomalies.

Note: This might be obsolete information.
With the latest Nvidia drivers, some users have reported that disabling Threaded Optimizations
has significantly reduced performance. (Down from 60 to 25FPS in one case.)

Upgrade your BIOS

Sometimes bugs or old specification limits in the BIOS on an older motherboard will prevent it from allowing the CPU or GPU to meet their potential.

Also, some vulnerabilities can be patched via BIOS update so that you wont lose performance due to mitigations.

If your manufacturer has an updated motherboard BIOS available, consider applying it.

Compile Darkmod for your own Hardware

The Dark Mod already contains many hardware specific optimizations and can detect when your system has the needed hardware so that it can accelerate parts of the engine.
Though unlikely, it is possible that MSVC++ or GCC compilers can improve the performance of the executable further when told what hardware you have.
You can try compiling The Dark Mod yourself and add any compiler configurations that are specific to your hardware.

Darkmod Compiling Guide

For Windows \ MSVC++ you may wish to add an AVX flag:

 https://learn.microsoft.com/en-us/cpp/build/reference/arch-x64?view=msvc-170

For Linux you can add -DCMAKE_CXX_FLAGS=-march=native to your cmake string.

Example:

 cmake -DCMAKE_BUILD_TYPE="Release" .. -DGAME_DIR=/home/user/darkmod -DCMAKE_C_COMPILER=gcc-11 -DCMAKE_CXX_COMPILER=g++-11 -DCMAKE_CXX_FLAGS=-march=native

Legacy Versions

If your Graphics Card ( GPU ) does not support OpenGL 3.2+ you can still play older TDM missions using Legacy TDM Versions
Some of the OBSOLETE settings referred to in this wiki can also improve performance in these versions

Legacy OpenGL 2.0 Versions

Older TDM versions ( 2.07 and older ) are able to run on OpenGL 2.0 or earlier hardware. If you cannot run the latest TDM versions, try an older release.
( Your hardware will still need to be able to run Doom 3 regardless of which TDM version you try. )

OpenGL 2.0 mode in 2.06 and 2.07 :

     seta r_nvidiaOverride "0"
     seta r_softShadowsQuality "0"
     seta r_useFBO "0"
     seta r_useGLSL "0"

( TDM 2.05 and older only support OpenGL 2.0 mode. No special configuration is required for these older releases. )

The easiest takeaway here is that if your Graphics Card supports OpenGL versions between 2.0 and 3.1,
this means that TDM 2.07 is your best option as it has the most optimizations (and features) yet supports
the older OpenGL versions.

Legacy Doom 3 Mod Versions

As a Doom 3 mod, TDM could render using any OpenGL standard that Doom 3 could ( between GL 1.1 and 2.0 / DX7 to DX9 hardware )
but most TDM versions use ARB assembly (GL 2.0) for water and glass effects so running TDM on DX8 (or lower) hardware
may result in some visual anomalies.

If Doom 3 doesn't detection your OpenGL support, you may need to force it via the r_renderer CVAR

     seta r_renderer "arb"

There are several backends other than the "arb" backend ( arb is for the oldest hardware ):

arb (basic)
nv10 (Nvidia GF1, GF2, GF4MX)
nv20 (Nvidia GF3, GF4)
R200 (Radeon 8500)
ARB2 (NV30, R300 and above) ( same as "best" ) ( OpenGL 2.0 )

Also the "Enhanced" interaction and ambient video settings require OpenGL 2.0 ( ARB assembly shaders )
(TDM 1.08 and newer have no legacy ( pre-DX9 hardware \ pre-OpenGL 2.0 ) support)

Finally, even in mod form TDM has higher specification requirements than Doom 3 due to higher poly characters and assets.
Further, since Doom 3 does not have some of the culling and multi-core optimizations that TDM 2.06 and newer have,
old missions can be even more taxing even when run on old OpenGL modes (without shaders, etc).
For example the mission "Rightful Property" on TDM 1.07 ( mod version ) has many areas that are below 20FPS
whereas TDM 2.07 (and newer) can render the same areas over 150FPS on the same hardware.

OBSOLETE Configure Video RAM

Change:


seta com_videoRam "128"

to the appropriate value (in MB) for your GPU in Darkmod.cfg

Eg. A 2GB video card would have 2048 there.


seta com_videoRam "2048"

Last resort: Upgrade your hardware

This whole wiki article is meant to assist players with making TDM run as best as possible on their current hardware.

That said, you may find that the needed compromises are too harsh or that some missions still do not perform
well enough even with an optimized configuration. As such, it may be time to consider hardware upgrades.

Before upgrading hardware it may still be advised to:

Ensure you have the latest Drivers for your hardware ( GPU, Chipset \ Motherboard, Audio )
Ensure your laptop is using the correct GPU
Ensure you are running in Uncapped FPS Mode and have proper Secure Boot Settings if you are using Linux
Ensure you have the latest OS updates installed
Ensure you have the correct Driver Settings applied
Ensure your Firmware is up-to-date ( Motherboard BIOS \ UEFI, GPU firmware, etc)
Open a support thread in the forums, especially if your hardware is above the minimum specifications

Modern games need a lot of computing power, and while you don't need the absolutely newest hardware to play them,
upgrading single components of your machine can help tremendously:

If you got less than 2 GByte main memory, consider upgrading your memory. This really helps to reduce swapping, which introduces quite noticeable slowdowns.
If you got a graphic card older than the Nvidia Geforce GT 8x00 series or ATI/AMD HD 4x00 series, consider upgrading it.
Upgrading the (spinning) hard disk to SSD / NVME "Solid State" storage should improved loading times, especially on 2.10 and newer.
For comparison, see Known System Configurations to see the weakest hardware known to run current TDM versions.

Upgrading your CPU is possible in most cases but can be quite complicated and the cost might be so high that upgrading your whole PC might be a better value.

Configuration Based Issues

A few configuration changes that players apply for performance benefit can cause unexpected problems.

A Warning about cm_backFaceCull

Some users have reported AI pathfinding and tread-milling issues with this enabled. While this can be the fault of poor map design or monsterclip placement,
one thing that can cause this is the performance cvar:


seta cm_backFaceCull "1"

This cvar does improve performance but it is not worth the hassle in most cases.
We recommend disabling it (cm_backFaceCull "0" ) unless you know the mission you're playing has been tested with it enabled.

OBSOLETE Blurry Briefing and Menu Screens

If you get blurry briefing and menu screens then in Darkmod.cfg make sure you do NOT have image_downSize set to 1.

Instead set it to 0.

This is fixed in TDM 2.05 (and later.)

Related FXAA and Blurry Fonts

( 2.07+ )

If you disable in-game AA in favor of FXAA in your driver settings, text will be a little blurrier. This is a known problem with FXAA in general.