Bug GPU Skinning spikes

Is this behavior normal? Can anyone confirm?
Running:
Unity 2021.3.8f1
Default pipeline, Forward

Scenario:
* Empty scene with ground and 121 armors (multiple parts - SkinnedMeshRenderers per armor) - NO animation.


*GPU skinning enabled, but the FPS every X seconds drops from 100 to less than 30. In the profiler I can see weird performance decreasing over time caused by GPU skinning. If disabled, it runs smooth without those ramps.

 

Another weird thing is, GPUSkinning performance on CPUs RenderThread is realy bad. Comparing to 2019, some weird logic is happening here.



Also in 2019, rendering was happening right before the end of the frame, in 2021 it doesnt even care.

 

Issue has been reported and reproduced as bug.

https://issuetracker.unity3d.com/issues/meshskinning-dot-update-takes-too-much-time-to-execute

 

Unity apparently didn't think it was a bug, but a feature. OP did you find a fix? We see our GPU Skinning performance decreasing over time, just as you have in the profiler.

Did you find a fix, apart from disabling GPU skinning?

 

For my case, I've solved it by combining multiple armor parts into single Mesh and SkinnedMeshRenderer (SMR) (with multiple material IDs)
=> previously I had aprox 10 SMRs per armor, so with every new instance, the bottleneck problem was raised significantly, but now I have 1 SMR per armor, so the problem is kept at low. It was enough perf gain for me till Unity deploys their "work in the pipeline that should bring significant performance improvements to this".