Speed of Lightroom 5 and LrC on new iMac

Hi,

We're sorry about the trouble with Lightroom on your M1 iMac. Would you mind sharing the exact version of Lightroom you're using along with the macOS version you're working on? Please ensure you have the latest version of Lightroom along with the latest macOS updates installed on the computer.

If you're using the latest version of Lightroom/Lightroom Classic, please ensure that the app has the necessary permissions on your iMac by follwing the steps mentioned below:

1. Go to the System Preferences for your Mac, then Security and Privacy, then select the Privacy tab.

2. Then select Accessibility from the list to the left & check if Lightroom is added to the list with a check mark in front of it.

3. If Lightroom is not a part of the list, please add it by unlocking the window first using the lock at the bottom left, then clicking the + icon & navigating to the Applications folder.

4. Also, grant permissions to Lightroom under Full disk access located in the same list as Accessibility.

5. Once done, restart the Mac & check if it helps.

If you're using Lightroom Classic, you can try optimizing the Preferences of Lightroom Classic using the steps suggested here: https://helpx.adobe.com/lightroom-classic/kb/optimize-performance-lightroom.html

Let us know if it helps!

Regards,

Nikunj