Micro Stutter Fix [Working 2020]

If you're one of the few people who have noticed that this game has a constant slight stutter, and you want to fix it, this guide is for you.

Intro

What you may know, but most have never noticed, is that there is a very slight stutter in the Doom 3 (id Tech 4) engine. It's been there since the very beginning and it happens on all platforms, a tiny hiccup about every half second. It (probably) affects all games using this engine[en.wikipedia.org]. Why does this happen? A user from my initial thread about this says:
The reason these stutters appear is because the whole physics engine works at exactly 62.5 FPS, and when you play at 60 fps the movement is interpolated unevenly to your framerate.

If you haven't noticed any stuttering, good! Move along. Don't worry about it, forget you have ever read this.
I have noticed, and searched the web for solutions, but most didn't work or weren't satisfactory. Finally I found something that works really well, and now I'm writing this guide to hopefully help somebody out there who is on the same search as I was.

Solution 1: Overclocking your monitor to 63hz

I haven't tried this myself but the same user from above swears by this method. Here's what they wrote:
Set your monitor to work at 63 Hz (which is slightly higher than 62.5 FPS) you'll quickly notice two benefits: the game will no longer have any stutters and Vsync will no longer cause any lag, making it the ideal DOOM 3 experience. Enjoy :)
WARNING!: Although most modern monitors are okay with Hz-overclocking it can be really harmful to a lot of older models, so first make sure, that your model is compatible with OC.
Tell me in the comments if this method works for you. If you can't or don't want to overclock your monitor read on for a different solution.

Solution 2: A bunch of configuration

This solution is a bit more intricate. But don't worry, I have hopefully explained it very simply and it shouldn't take more than 20 minutes to set everything up.

Step 1: Unlocking the framecap

Short version: Create or edit the AutoExec.cfg file in the steamapps\common\Doom 3\base\ directory. If you use any mods put it in that mods folder instead. The folder for Resurrection of Evil is called d3xp.
Add the following commands:

seta com_precisetic 0
seta com_fixedtic 1

This will remove the 60 FPS cap from the game and fix the stuttering, but also makes the game run way too fast. We'll fix that in the next step.

Long version: This is the same process explained in more detail, for anyone that hasn't worked with AutoExec files before or just needs a little help. Otherwise, move on to Step 2.
Find the directory where Doom 3 is installed. In Steam, this is easy: right click on the game name, click Properties, then, under the Local Files tab, click Browse local files...
Now go into the folder called base. If you want to play the expansion pack, Resurrection of Evil, go into the folder called d3xp instead, or if you use any mods, go into the respective mod's folder.
Is there a file called AutoExec.cfg ? Open it in Editor and paste the two lines from above, then click save.
If there isn't, Right Click → New → Text document. Call it AutoExec.cfg. Open it in Editor and paste the two lines from above, then click save.

Step 2: Vsync

Fixing the speed problem is as simple as turning on Vsync, (either in-game or in your graphics card settings, I recommend the latter) which will limit the game's speed to 60 fps again.
But with that comes another problem that needs to be dealt with. Vsync generally adds input lag, and I feel it's very noticeable in this game. Here's what to do against it:

Step 3: Limiting frame rate to 60 fps

In order to decrease the Input lag caused by Vsync you need to limit the framerate to 60 fps. How you do that depends on the graphics card you have:

For Nvidia cards:
Download a program called Nvidia Inspector[www.guru3d.com]. It allows you to tweak more settings than the standard control panel, including the one we need.
Install it anywhere and run it from the Start Menu.

Click the little tools icon next to the driver field.
In the top left box select Doom 3
Next to frame rate limiter select 60 fps (exactly that, anything else will reintroduce stuttering)
You can also turn on Vsync from here, if you haven't done so yet
Finally, click Apply changes

For AMD cards:
Download a program called RadeonPro[www.radeonpro.info]. It allows you to tweak more settings than the standard control panel, including the one we need.
Install it anywhere and run it from the Start Menu
Click the little add Profile button at the top
Navigate to your Doom3.exe and select it
Under the Tweaks tab, check Dynamic Framrate Control and select 60 in the box
You can also turn on Vsync from here, if you haven't done so yet
Changes are saved automatically, as long as the right profile is selected on the left

Disclaimer: Don't have an AMD Card myself, but this seems like the correct way to do it. Please comment if this doesn't work.

Alternative program, for both card manufactures:
RTSS[www.guru3d.com], a program providing frame rate monitoring, on-screen display, and some other features.
A user commenting on my initial thread about this says this is the better solution as it provides more stable frame times. On my machine, however, no versions of this program work correctly, no idea why. But it might work for you, so here are the steps:

Download and unzip anywhere
Install it anywhere and run it from the Start Menu.
Find the symbol in the system tray (bottom right of the screen) and click on it
Click the big + in the bottom left, navigate to your Doom3.exe and select it
On the right, type in 60 next to framerate limit
Minimize RTSS

And you're done!

The one problem with solution 2 over solution 1 (overclocking) is that apparently the audio in cutscenes goes out of sync. I've played through the whole game and haven't noticed that, so it's probably a very small effect.

Note, that Step 3 isn't exclusive to this game. Any game with Vsync might show lowered input lag if you additionally limit the framerate to 60 or maybe 58 fps. I try to completely turn off Vsync in most games to prevent the additional input lag, but this trick is a very good second choice where that isn't possible or preferable.

Hope I could I help you! Have fun playing!

[Javert]

In addition to this guide, 60fps on a big screen doesn't feel smooth, to fix this use a Frame Generation tool:

- "Lossless Scaling" software available on Steam (LSFG 4x; Performance mode enabled to avoid noticeable input delay)
- Doom 3 must be launched in Windowed mode (autoexec.cfg in Doom3/Base folder, with seta r_fullscreen "0" line) => Lossless Scaling will turn it in fullscreen immediately when using CTRL + ALT + S).

The game now works like a charm at 240fps.

[Geralt_Boladao]

Can confirm this works as of 2024, i used doom 3 redux mod to some QoL changes, and foubd it weird that a 3070 was having sttuters on a 20 year old game, this solved the issue, thanks.

[hiandbye]

@Lucifer, well good look with what you're doing. All I know is that this helped me and a couple other people back in the day. Maybe it's broken now or maybe it doesn't work on every setup.

[Lucifer17761945]

Your guide literally doesnt work. I know 100% as im a modder that has been working on a project in this engine for over 4 months straight of full time work. And I have more experience with DOOM 3 and Quake 4.

The best it does is tells people about comfixedtic 1 which mostly helps, but its still a dumpster fire of performance targeting 60fps solid. People arent crazy, its dropping frames. Some of them are blind though for sure. Its very common for people to turn off vsync and they recommend people do. G sync isnt going to fix it. It just drops 1 actual frame instead of duplicating it with vsync.

[Lucifer17761945]

You can fix it in the editor but giving people more information is pointless since im realistically the only person whos going to fix it. Yes the fix is in the editor and its an insane amount of work.

63hz doesnt solve the problem at all because its not mathematically precise which is causing the problem in the first place in the less broken but still broken comfixedtic 1 mode. Revise your guide by actually testing it because you will see it still drops. And I know why it drops. Specific trigger events. I found a workaround.

https://www.moddb.com/mods/prey-2006/#8729337


Im going to launch the VR version for free. Not only will I fix the performance issue, im going to launch the highest end version which has superior texture and shader resolutions to DOOM Eternal by a SIGNIFICANT margin. I have over 100GBs od DDS files unpacking all the .pk4 files.

[krokodil]

this game is the biggest pain in the ass on a CRT in 2024

[Lucas80]

wouldnt it be easier to just add seta com_maxfps "60" to the DoomConfig.cfg file

[General Higgs]

I have only had issues with large stutters and it was fixed by changing the power level in the Nvidia Control Panel to prefer maximum performance.

[marsupial]

Wow, it works! Many thanks for putting your time to do this guide, man. I admire your commitment to community service.

[Parasite Steve]

Thank you, it worked :D