Strong noise appearance on textures with displacement

[bananadrone]

Hello everyone I hope you are doing well.
I am deeply concerned about this render of mine that I did last night. I rendered it at 8k for 6hours on my 5900x with 71 passes and the noise you see still persist on the stone walls I got from Quixel Megascans. I tried to reset my corona settings but no luck. I will provide information as much as I can. THank you :)

[romullus]

Hi,

I see strong noise everywhere in the picture. There's noisy areas with clear boundaries next to relatively noise free areas, this tells that it could be an issue with adaptive light solver. What Corona version do you use? If it's not the latest official release, i strongly recommend to update, since many similar issues has been fixed in the newer versions. I also see big amount of fireflies. This can indicate that there's some incorrect material (-s), especially if they're near strong light source (extremely bright spot lights that illuminates tree canopy would be my prime suspect). You can try to render the scene with default grey material override (use preserve displacement feature if you suspect that that's the culprit) and see if noise and artifacts are still present or not.

[romullus]

You didn't mention if you're using lightmix - you can easily get excessive amount of noise if your lightmix settings are too extreme.

[maru]

You have some LightMix elements set to 15x their original strength, and some to even 50x. This is bound to result in heavy noise / artifacts. LightMix should (usually) be only used for minor light intensity adjustments.
Here are two possible solutions:
1) Try balancing the light intensity more in your original scene (so increase the intensity of lights which you wish to increase through LightMix). Then you will not be increasing their intensity from 1 to 50, but let's say from 25 to 50.
2) Use the ">Scene" button in LightMix to transfer all LightMix settings into your scene lights. Note: this will change your light properties and cannot be undone!