slow rendering volumegrid in stable build.

[Hos]

I am working on a project with a lot of explosions. For the explosions I use the volumegrid objects. I use 4 different vdb fluid caches in about 60 volumegrid objects.
The rendering speed in the stable build, compared with the nightly builds is extremely slow. Or you can say that the render speed in the nightly build is extremely fast.
I would like to use the nighly build to render the explosions on our farm, but the volumegrid objects will crash vray on linux computers in the nighly builds.
There are some other problems with rendering volumegrid objects in the stable build on linux. I cannot use the "use lighting" function. When I do I get a lot of infinite color pixels in the fluid.
And when I use light cache as a secondary bounce in the GI options in the render settings, I get a lot of strange colors all over the rendered image.
All these problems we only get with linux. On windows everything will render fine.
Are there any tips for speeding up volume grid rendering? Or are the developers aware of the problems with volumegrid rendering on linux?
I emailed to the support about this problem, but we don't get any response. There could be a chance that my mail is on a blacklist.
thanks,
Arjan

[yolov]

Can you share a scene that's crashing on your end? Also any other scene that's causing you troubles would be good to have for investigation and testing purposes.

[vlado]

I would prefer if we fix the nightly build if possible, so any way that we can reproduce your issues is very welcome (scenes, cache files etc).

Best regards,
Vlado

[Hos]

Yes I made a test scene that fails to render on our linux computers. I also included the render logs in the zip.
https://backdoor.houseofsecrets.nl/d...=VDB_Error.zip

[yolov]

This is already logged in our system. I'll let you now when we have a fix for this. In the meantime, it would be greatly appreciated if you could share any other scenes that you're having trouble with (invalid colors, crashes, etc), so we can take a look and hopefully fix whatever bugs there are.

[ivaylo.ivanov]

Do you use the latest stable 3.0 nightly? There was a parameter called "LC Subdivs Reduction", better not render with such builds. We changed it's meaning silghtly at some point and it was renamed to "Light Cache Undersampling". You will get very bad performance if you export a scene with area lights from the nightly and render it with old stable/official 3.0

[Hos]

Right now we export with the old stable/official build and render it with the same build on the farm on linux. I only use irradiance as a primary bounce and no light cache as a secondary bounce.
The test scene was exported with a nightly from about two weeks ago.
I will upload some test scenes soon for the other problems I talked about.

[yolov]

The crash is now fixed in the nightly builds.