Slow performance eevee - metallic material weird issue

Hi there,

This is a weird bug in Blender 2.8. When you have multiple objects with metallic shaders, your scene will suddenly slow down the performance drastically. It magically becomes buttery smooth again when the metallic value is decrease from 1.0 to 0.99…

(i’m using 2.82 in the video)

can you share a .blend with the issue ?

Here is the file.

200227_metallic slow performance problem.blend (1.6 MB)

Thanks, I don’t have any issues with your file…
Can you test with lastest blender build :

You can also try to restore blender to default settings and see if it’s not an addon that do something here…

Lastly this can be an hardware issue , but it sound weird …

I can recreate the error with a fresh install of blender with factory settings :S weird stuff! I am on a mac btw.

This is definitely an issue with the Apple AMD drivers. The driver will continually recompile the shader over and over again, which is why the CPU spikes and the viewport lags. Something Blender is doing is triggering the bug obviously, but using the integrated Mac Intel GPU works fine. The reason the metallic setting matters is that Blender optimizes which GL shader it will use for the Principled BSDF node depending on which values were used. So something in those GL shaders is probably triggering the recompile bug.

SCCompileShader is taking all the time in this profile:


Thanks for the in depth look. I hope this issue will be sorted out soon!