P: Slow UI when using Mac and Custom Display Profile

casper_pedersen_7749526, I was responding to the issue presented by the OP who stated that...."Since upgrading to Lightroom Classic v10.0, all UI-related functionality is painfully slow. All editing functions are working correctly and quickly but scrolling through the catalogue or even scrolling a side panel is taking many long seconds to refresh. Unreasonably long."

He stated that HIS issue was with the UI, so I thought I would offer a potential band-aide that might make it easier for him to use the software until the next update.  Perhaps YOUR issues are different than the OP's issue, who stated very clearly that he is having an issue with the UI only. You may be 100% correct about your assessment/solution, but I was just trying to be helpful.  Perhaps your advice would be more valuable to him.
 

That's why I ask them to search, or ask me, whatever they don't understand. I can't TELL you how many times I've fixed application issues with Onyx in my 25 years as a Mac IT Engineer! 99% of these users, if I wasn't there, would do more damage if they tried to use Terminal! Reinstalling the OS, that's what Windows techs do!

PS-you don't KNOW whether it's Lightroom Classic OR the Mac OS, or both, it's too complex! Even if LRC is the only app crashing, you STILL DON'T REALLY KNOW! Note how the majority of Mac users are NOT having this issue? What does that tell you? It may be (partially) your OS.

So I've made some progress testing on my system and would be glad if some of you with similar hardware (Intel i9, Radeon VII 16gb, 128GB DDR4, Samsung 970 Evo NVME) could test the same. 

Before v10 it made little to no difference if I had the RAW files on the SSD or on a fast, internal HDD. After the v10 update, my daily catalog wasn't usable anymore, to slow. Deactivating GPU support helped a little bit.

This morning I selected the 1400 images I'm working on right now and exported them as a new catalog (including previews AND RAWs) to my NVME drive. Deleted lots of old stuff from this drive to make sure, I have at least 1/3 free space. Then opened the new catalog in LR, already much smoother. Went to LR settings, reactivated full GPU support, emptied Camera RAW cache und video cache and now LR is running smoother and faster as ever before 🙂

Onyx is a very powerful tool for people who know exactly what they're doing. It combines many useful things that one could execute within Terminal with a few lines as well but in an easier way. What's dangerous about this for "regular users" is it's not only easier to do helpful things but also to mess things up. 

Most of these kinds of repairs are not necessary on a regular MacOS installation. And in the few cases when things got really messed up it usually takes (thanks to iCloud) only little time and effort to reinstall MacOS and really start new. 

Reality is painful to those who live in the the world of wishful thinking. Interesting how you can't identify a single error in my comments. 

Same problem here:

2013 MacPro 3.5 GHz 6-core Xeon X5, 64GB RAM, AMD FirePro D500

v10 UI so slow it is not usable.

@brian_corrigan_7501389 the problem is not the UI, the problem is how it deals with data. LR9.2 was working almost flawless for me, LR10 is a piece of ... software.

*carlos_cardona  some people swear to Onyx, some people don‘t... that tool can actually create problems it you don‘t know what you do. Also why would you try to repair something which is not broken, the problem is Adobe Lightroom, not Apple MacOS. And people are seeing it with Mojave (me), other people with Catalina ... this is a broken piece of software. 

Can you just stop? I've read this whole thread and you've repeatedly spouted nonsense. You obviously don't know what you're talking about, but feel compelled to advise anyway.  

Please, please stick to topics that you know something about, its not helping anyone. 

Bill, you're way out of your depth here. Time to move on.