Error: no GPU matching requirements found

[gremmler4ARLU]

I'm getting this error with different versions of Arnold. Last stable version: 4.6.6.2. Higher versions stop render in the middle of an image sequence or crash C4D. Console: "device selection failed. No matching device(s) have free memory greater than options.gpu_default_min_memory_MB threshold [c4dtoa] 00:00:00 10829MB ERROR | [gpu] no GPU matching requirements found for GPU-rendering"

Specs: Ryzen 9 5950X, 64GB RAM, Win10, Nvidia 4090, C4D 2024.x

Any suggestions?

[peter_horvath]

Sounds like the GPU runs out of memory. Could be a bug (like some data is not deallocated properly) or perhaps the given frame actually needs more memory than available. If you enable debug logs in Arnold Render Settings > Diagnostics, you should see the GPU memory usage each frame.

[gremmler4ARLU]

Attached a Log screenshot of every 100th frame. It seems the memory counts up. Although there is no significant change in the scene and no textures. Materials are mainly using vertex maps. 310.log was the last frame before the PC freeze. Had to reboot. Any ideas?

[peter_horvath]

Can you send us the full debug level log files of the entire render? Your screenshot only shows the CPU memory at certain points of the render process. A debug log has more details information of how much memory is used by which components and shows VRAM usage as well.

[gremmler4ARLU]

Sorry for the delay. I switched to another scene where this error don't occur. However, it still happens with some scenes and I can't identify why. It just happened again in the middle of a sequence rendering and when starting the render again and activate Log (without restarting C4D) the attached log appear on the first frame.

[peter_horvath]

The log indicates, that the GPU has not enough memory:

GPU 0: NVIDIA GeForce RTX 4090 @ 2520MHz (compute 8.9) with 24563MB (317MB available) (NVLink:0)

Only 317 MB available, that's why you have the error of "no matching requirements found". The minimum required memory to start rendering in 512 MB by default.

This is very likely due to a memory leak in Arnold which we have to fix. Do you have a denoiser, either OIDN or Optix in the scene? Or an OSL shader maybe? It might be caused by the OIDN denoiser running on the GPU. If that's the case, you can try to switch to CPU mode.

[gremmler4ARLU]

yes, I've seen the low memory in the log too. I use denoiser (OIDN/OptiX). From my experience, it happens  increasingly with the new Arnold version. Version 4.6.6.2 seems more stable. Maybe this helps to identity the problem.

[gremmler4ARLU]

Using OIDN in CPU mode helped. But now a similar error appeared (C4D, Arnold and Nvidia drivers are up to date):

[c4dtoa] 00:00:01 8210MB ERROR | [gpu] CUDA call failed : (700) an illegal memory access was encountered
[c4dtoa] 00:00:01 8210MB ERROR | [gpu] Exception thrown during GPU execution: an illegal memory access was encountered
[c4dtoa] 00:00:01 8157MB WARNING | Due to an error, the CUDA context could be corrupt and GPU rendering may not function. If further errors occur, please restart the application

The error sometimes causes the PC to freeze and after reboot, the error appears again.

[gremmler4ARLU]

Is there are solution for this meanwhile? In general, it seems OIDN CPU is a bit more stable than Nvidia. But rendertime increases with OIDN CPU. It appears on image sequences in high resolutions but less content. Although most of the image area is black, the OIDN denoiser takes up to 20 seconds longer than Nvidia to process a frame.

[peter_horvath]

Have you tried the latest version, C4DtoA 4.7.5? Is this still an issue? I guess it's expected that OIDN CPU is slower than OptiX, although 20 seconds sounds a lot. What's the render resolution? What about OIDN GPU, is that also slow or unstable?