32 GB 2400 MHz DDR4 RAM Radeon Pro 575 4 GB GPU Lightroom "Use GPU" preference set to "Auto"
Camera Raw cache set to 150 GB
Generally working with DNGs from Canon R5 raw files
Lightroom often freezes entirely when working in the Develop module, becoming completely non-responsive with MacOS giving the spinning pinwheel. Some freezes are short, but most are quite long, taking several minutes to recover, if it even does. Lightroom often does not recover from freezes and has to be force-quit, and this generally seems to leave subprocesses running on the system which must be killed in order to get Lightroom to start again with any kind of reasonable performance (i.e. one needs to open Terminal and run `ps aux | grep Lightroom` and then `kill` relevant processes). Lightroom will launch again if these subprocesses are not killed, but the performance is horrible. This problem with freezing started with one of the more recent updates (perhaps Lightroom Classic version 10 -- not entirely sure) and the behavior has been consistent through every single update.
Disabling the Lightroom GPU preference is not a viable solution -- it results in degraded Lightroom performance more generally, to the point that suffering through freezes is actually preferable. Making the Camera Raw cache size smaller, or larger, don't seem to have any impact. On the whole this problem makes Lightroom nearly unusable for anyone working on a deadline or who simply does not want to be stopped every N minutes by a full freeze of the software.
We're sorry about the trouble with Lightroom Classic. Does Lightroom Classic continue to freeze while editing with the option to Use Graphics Processor disabled? If not, then the issue might be due to the graphics card itself.
If Lightroom Classic continues to freeze with the graphics card disabled, you can check if Lightroom Classic has the necessary permissions on your Mac by following 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 Classic is added to the list with a check mark in front of it.
3. If Lightroom Classic 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 Classic under Full disk access located in the same list as Accessibility.
5. Once done, restart the Mac & check if it helps.