Lightroom Classic 9.0 slow on macOS

Are you sing Acronis Active Protection?

see: 

: https://feedback.photoshop.com/photoshop_family/topics/lr-cc-9-update-extremely-slow-after-update?to...

No idea if a better workaround exists than in that post

Hi there,

We are sorry about the issue you are facing with Lightroom Classic version 9.0.

Would you mind checking the below mentioned details and performing the steps to check if it helps?

1. Go to Preferences > Performance and increase the Camera Raw Cache size to 10.0GB or more.
2. On the same tab, check the option to Use Smart Previews instead of Original for image editing and uncheck the option to Generate Previews in Parallel.
3. On the Performance tab itself, select off from the drop down for Use Graphic Processor
4. Go to the General tab and check the box to Replace Embedded previews by standard previews during idle time.

Once you have made the above-mentioned changes, quit and relaunch Lightroom Classic prior to testing the application.

You can also try: https://helpx.adobe.com/in/lightroom-classic/kb/optimize-performance-lightroom.html

Regards,

Nikunj