Mine is at 6144 and says 6144. Never changes. 

@buspelle Are you editing the correct user config file?  I made this mistake.  I can't remember which, but I was editing either an old backup, or the old 2020 file.

Now I am editing the correct file as below: -

{Shadows
        MaxSliceCount 4
        Size 6144
        DLightContributionCullingThresholdS0 0.100000
        DLightContributionCullingThresholdS1 0.100000
        DLightContributionCullingThresholdS2 0.100000
        DLightContributionCullingThresholdS3 0.100000
        OmniContributionCullingThreshold 0.000000
    }

An easy way is to download and use an absolutely excellent and free little tool called MSFS2024 Toolbox.  It will find the correct user config file for you.  It can also help you with other useful settings.

https://flightsim.to/file/94636/msfs2024-toolbox

 

By the way, my slider in MSFS 2024 now shows 6144 (just as St Mawgan says above), but if you adjust the slider, the setting will go back to 2048 because that is the highest it can move inside the sim, so once you have it set on 'custom' and set it in the config file, don't adjust it in the sim or it will keep going back to 2048, and the only way to get it back is to edit the user config file again.  I wish Asobo would adjust this, as it is one of the best tweaks you can do in the sim.

I have found 6144 to be the optimum setting.  Even my old 1080Ti graphics card had no performance hit with this setting.  There is a reason for this setting, it is a multiple of 1024, (x6)

I have experimented with 8192 (x8), but the shadows then looked unnaturally razor sharp, and a little bit of a performance hit started creeping in.  6144 is easily adequate.

The easy way is to turn on raytraced shadows, but these only apply to the cockpit anyway, and also introduce a performance hit even on my RTX4080, so I don't use them.  No need with the 6144 tweak.
 

Edited October 3, 2025Oct 3 by bobcat999

Super!!! 👍🤗👍🙏 I will try that when i get home i a couple of hours! 👍 Thanks! 

Best regards 

Per 

1 hour ago, buspelle said:

Super!!! 👍🤗👍🙏 I will try that when i get home i a couple of hours! 👍 Thanks! 

Best regards 

Per 

Good luck!

This is true: there are more possible variations in the msfs settings than there are stars in the universe.

It's hard for me to find the perfect setup. That's why, following the advice I found here in the forum, I used ChatGPT to write my UserCfg.Opt file for me. I'm not sure how many billions of computations a computer chip does in one second, but It out performs ability at trial and error. You can for instance force ChatGPT to set the shadows very high as it makes your UserCfg.Opt. All you have to do is ask. 

I would have had no clue how to do this, until I read that thread and the true gurus made it easy to understand for even me.

https://www.avsim.com/forums/topic/676573-chatgpt-one-command-how-well-is-your-sim-optimized/#comment-5537701

This is true: there are more possible variations in the msfs settings than there are stars in the universe.

It's hard for me to find the perfect setup. That's why, following the advice I found here in the forum, I used ChatGPT to write my UserCfg.Opt file for me. I'm not sure how many billions of computations a computer chip does in one second, but It out performs ability at trial and error. You can for instance force ChatGPT to set the shadows very high as it makes your UserCfg.Opt. All you have to do is ask. 

I would have had no clue how to do this, until I read that thread and the true gurus made it easy to understand for even me.

https://www.avsim.com/forums/topic/676573-chatgpt-one-command-how-well-is-your-sim-optimized/#comment-5537701

Have been running 4096 for over a year. Never knew I could pump it up to 6144.. Life changing, this is on a pretty basic GPU 2080. Minimal performance impact, major visual impact. The cockpit shadows are absolutely amazing. Thanks!

On 10/2/2025 at 5:46 PM, JonathanC said:

That’s only inside the cockpit

Not entirely true, they're also in walk around mode.

Edited October 3, 2025Oct 3 by Tuskin38

22 hours ago, Mace said:

Q8Pilot is using 4096, but perhaps that has changed?  (Q8Pilot is a youtube who did a vid about it)

That video was for XP12.    It's a similar issue with XP12 and 8092 can be set in the cfg and it drastically improves the cockpit shadows.     I didn't think it was possible in MSFS?

Just now, JYW said:

That video was for XP12.    It's a similar issue with XP12 and 8092 can be set in the cfg and it drastically improves the cockpit shadows.     I didn't think it was possible in MSFS?

He, or someone else like IslandSimPilot, did indeed do a video in MSFS about using 6144...that's how I found out about it.   Yes it is possible, I was using this little tweak in MSFS2020 a couple of years ago already.

1 hour ago, Tuskin38 said:

Not entirely true, they're also in walk around mode.

Didn't know that, thanks. 

51 minutes ago, JYW said:

That video was for XP12.    It's a similar issue with XP12 and 8092 can be set in the cfg and it drastically improves the cockpit shadows.     I didn't think it was possible in MSFS?

Oh, if you mean "you didn't think 8092 was possible in MSFS" then I do not know.  The highest I have used is 6144 and it looks really good to me.

These are the typical 'binary multiplier numbers'.  1024, 2048, 3072, 4096, 5120, 6144, 7168, 8192, 9126, etc...
The reasons for going up in this sequence are not complicated, but would be long-winded to explain, but basically computers have worked like this for years, especially with textures, due to the binary systems they use.

Although the slider in MSFS (both versions) is limited to 2048, you can use any number in the user config file, and it will work, it is just that 6144 seems to be the optimum for a lot of people, and for a few reasons.

1.  4096 is still a bit soft and feathery around the edges.
2.  8192 starts to introduce a slight performance hit.
3.  with 8192, the shadow edges start to look razor sharp and a bit unnatural - you can try this yourself.

So for me and many others, even running at 4k, we have found 6144 to be the sweet spot.  I am really happy with it for sure.  I just wish Asobo would allow more movement on the slider.

I have tried ray traced shadows with the standard 2048 setting.  For me it was no better than 6144 bitmapped, but it did give a slight performance hit, which has been proven by others in performance tests.
But this is obvious and would be expected, as every game I know suffers a performance hit with ray traced shadows turned on. 

At the end of the day, use whichever system you like.  Not much in it really.   All good.

The problem left now is the screen space shadows/reflections that cause weird issues around the certain objects (like window frames) and shadows/reflections on water etc. but I don't know if they will ever solve that, as applying ray traced shadows to the whole environment would be really costly performance wise.  In any case, we all just seem to live with it.

Edited October 4, 2025Oct 4 by bobcat999