Thank you for your time. @arunoda @spikeyxxx @jlampel
After searching for Optix and RTX, I thought I may have to throw my GTX 1080Ti into a trash can, here is what I’ve found:
1. Blender Preferences -> System -> Cycles Render Devices -> OptiX -> GeForce GTX 1080Ti was not automatically checked by Blender 2.90.1
2. If this is not checked, enabling viewport denoising will crash Blender by setting Cycles Render Properties -> Device to CPU or GPU Compute.
3. If this is checked, enabling viewport denoising will crash Blender by setting Cycles Render Properties -> Device to CPU. ( @spikeyxxx‘s settings crushed too, may be he has a RTX GPU?)
Somehow, I’ve got Cycles viewport denoising working on Blender 2.90.1 + GTX 1080Ti by
1. Make sure OptiX -> GeForce GTX 1080Ti is checked
2. Set Cycles Render Properties -> Device to GPU Compute
Cycles viewport denoising is FANTASTIC!
Hope this may help people who are facing the same problem.
