I've been doing some testing with Karma XPU and most of the time the RAM usage is manageable however sometimes the memory usage spikes so high on both system and VRAM. It causes Optix fail and the GPU not to render at all I suspect.
Feels like some kind of memory leak or something in the scene misbehaving with Karma specifically.
Rendering the same scene in either Arnold or Redshift yields lower memory usage.
Karma XPU:
The logs only eventually say:
KarmaXPU: device Type:Optix ID:0 has registered a critical error , so will now stop functioning. Future error messages will be suppressed
The render does start and complete on the CPU.
Example of Arnold GPU memory usage on the same scene. (Shaders, mesh properties, render settings, amount of AOV, etc. matched as best possible)
So we're getting a "74 GB" difference in system memory usage, which is quite significant.
I've also tested the difference between Karma CPU and Arnold CPU.
Karma CPU = 83 GB
Arnold CPU = 26 GB
There is alot of instanced grass geo, which in Arnold for example has x1 Subdiv iteration.
For Karma, I gave it the catmullClark subdiv scheme and lowered the dicing quality to 0.01 to hopefully optimize it.
Karma isn't outputting any logs into the Output Console or anything relevant (like a scene/render report) in the Log Viewer.
Not sure how to provide any additional information needed.
all the best,
amwilkins
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Houdini Core 20.0.653 - Py3.10
