P: Slow UI when using Mac and Custom Display Profile

When you upgrade from 9 to 10, any change in catalog size is probably not due to a change in previews, since re-rendering the entire catalog would take quite a long time.

I have tested individual folders, and found that re-rendering the previews to 1:1 doesn't improve things.

Same Here...

MAJOR slow down in virtually every way.

Also experiencing similar issues.  I provided feedback under a different post: https://feedback.photoshop.com/conversations/lightroom-classic/lightroom-classic-v10-ui-performance-degradation-on-mac/5f9211a335f40c2520c1881f

Interesting, maybe the solution is to delete the previews file (or remove it from the folder) before converting, then let it recreate itself under V.10? In case you don't know, deleting it means when you go to a folder you will, at first, not see your edits while LR Classic churns to create a preview for each image, then they will slowly appear correctly (all your edits are still in the DB).

In this forum https://community.adobe.com/t5/lightroom-classic/lightroom-classic-10-catalog-size/m-p/11546054?page=1#M209461

Someone mentioned file sizes. So I looked to see and this is what I found.

I have both LR9.4 and 10 running. 10 is not usable because of the slowness but the upgraded catalog is the same as what I am running on 9.4. Your mention of catalog size got me checking my catalog. Both catalogs stayed at 1.3GB but the Previews file shows a huge difference. 9.4 previews is 21.23GB while the 10 previews is 52.5GB. I wonder if this is part of the problem making 10 so slow it is not usable.

I have my RAWs on an external SSD but my only inputs are USB 3 to the iMac.  I will try putting the RAWs on my internal iMac SSD and see if that helps when I get home this evening.

LrC10 does not run fine on Mojave nor Catalina as I have machines running both.

There is no option to run in Low Res Mode via Get Info on Mojave for the LrC app.

I haven't checked on Catalina but that isn't my computer I normally use Lr on so I really don't care if it has it or not.

And no I'm not going to run Onyx as that will do nothing to help with this.  Going back to 9.4 fixes everything.  10.0 is broken on MacOS and needs to be fixed.

Same Here.. Similar Config.

2013 Macp Pro

12 core

64GB Ram

2TB Internal SSD

Dual AMD FirePro D700 6gb Graphics Cards

GPU acceleration enabled

Catalina 10.15.7

I'm running almost exactly the same setup except for 64GB 1866 MHz DDR3. LR10 became unusable. I tried all of the suggestions from the Facebook Lightroom User Group and then some to no avail. I finally threw in the towel and uninstalled 10.0, reinstalled 9.4 and brought LR back to life. I really can't understand how PremierePro, Photoshop and all of the other Adobe CC apps are just fine but Light Room slowed down at least 40%. 

I know this thread is for LR10 and I posted my experience above, I wrote that on my PC it works ok but on MBP it's unusable. So today I tried to edit one photo (24Mpx) in Photoshop on my beefy PC and it was horrible. In a very basic document with few layers, I couldn't even brush one layer mask without stuttering. On the same machine, I edited lots of complex files without any problems. Something is wrong with this update 😕😕