Select And Mask: slow performance on fast Macbook Pro Photoshop 21.0.2

Your other thread shows GPU issues and conflicts. You have two GPUs - an AMD and an Intel. Photoshop is seeing both and enabling neither for OpenGL and both for Open CL. The GPU sniffer , which detects the GPU, has crashed but with a very strange date of 22 April 19 . There are a couple of other things that look strange in that system info.

See sections 7 &8 here
https://helpx.adobe.com/uk/photoshop/kb/troubleshoot-gpu-graphics-card.html

Hello, your post has not been deleted, it drifts behinds newer posts, you an always see it by clicking on your avatar...

here it is:

https://community.adobe.com/t5/photoshop/select-and-mask-slow-performance/td-p/10852037

Hi there,

Sorry that Select and Mask is working slower than expected in Photoshop 21.0.2 on your MacBook Pro running Mac Os Catalina. Please checkout the steps below:
 
1) Try going to the System Preferences of the macOS, then to Security and Privacy and add Photoshop to the Accessibility under the Privacy tab. Also, grant permissions to Photoshop 2020 under the Files and Folders section.
2) Turn on the Legacy Compositing option in Performance preferences. Choose Edit > Preferences > Performance (Windows) or Photoshop > Preferences > Performance (macOS). Select Legacy Compositing. Quit and relaunch Photoshop
 
Let us know how it goes.
 
Thanks,
Akash