P: Bring back the ability of Enhance to run in the background. (LrC)

Don't forget to delete the .xmp sidecars before reimporting the photos.

Thank you for your help.

Since I plan on re-editing the 262 without using the AI Denoise I will go through the removing from catalog and re-importing.  

I also noticed Lightroom using twice or more of memory when using the AI so with that and the space issues I'm just going to stay clear of AI.

@D.L. Dietz: "So turning off the automatic write to XML will stop the issue going forward but what can I do to reduce the current size of the catalog other than re-editing/re-denoising the 262 files I used AI Denoise on?"

If you want to re-edit the photos, then remove them entirely from the catalog and reimport.  Otherwise, LR may not recover the catalog space of those photos, even if you reset their settings and clear their history (which sometimes does, sometimes doesn't recover the space).

You can recover the catalog space without losing the photos' edits with this song and dance:

1. In Library, make a virtual copy of the photo.

2. With the virtual copy selected, do Photo > Set Copy As Original.

3. Select the new virtual copy (which was the master prior to step 2) and delete it from the catalog.

4. Repeat for all the other photos.

5. Do File > Optimize Catalog (which may or may not be necessary).

This will preserve the photos' edits but lose their history.   

Unfortunately, the Set Copy As Original command only applies to the most-selected photo, not to all selected photos. So you have to do the procedure above one photo at a time. You could likely automate it with a keyboard-macro utility, such as Autohotkey on Windows.

@johnrellis Any Enhance if part of the edits saved into XMP gets stored also in catalog.
Super Res makes the catalog get big really fast.

One solution is, as you said, to disable auto save into XMP and also never save manually.

Another solution is to do all Enhance in Virtual Copeis AND be sure to NOT save them as snapshot otherwise they become part of the data that gets saved into the XMP.
Using VC the XMP will stay light, the catalog will not be bloated as well.

I recommend everyone to not save Enhance into XMP unless totally necessary and rely on VC

.

So turning off the automatic write to XML will stop the issue going forward but what can I do to reduce the current size of the catalog other than re-editing/re-denoising the 262 files I used AI Denoise on?

I use denoise all of the time. Currently running 14.4 [ 202506051112-5918896a ]. I like the fact that denoise is non-destructive, however, the fact that it doesn't run in the background is SUPER FRUSTRATING. I'm sure for things like this Adobe says, "man we can't win!" but I can't do anything while it's running so I am thinking of reverting to the previous version. 

@D.L. Dietz: "On 2025-06-20 my Lightroom Catalog-v13-3.lrcat file was 1,947,116BK.  After using the AI Denoiuse on just 262 photos by 2025-06-28 it had increased to 3,480,836KB."

The new Denoise has a bug -- when you've enabled Catalog Settings > Metadata > Automatically Write Changes Into XMP, LR copies the Denoise data from the .lrcat-data file into the .lrcat file before writing it into .xmp sidecars:

https://community.adobe.com/t5/lightroom-classic-bugs/p-automatically-write-changes-to-xmp-can-t-be-used-with-denoise-on-large-numbers-of-photos/idi-p/15393188

In your case, that's an average of about 6 MB per photo, which is a typical size for computed Denoise data.

The only workaround known so far is to disable Automatically Write Changes Into XMP (which I've done, grumpily).

Just adding my voice to the thread.  My issue is being locked out while running Denoise.  I typically would move onto Library and start looking for my next keeper to edit and start editing it while the Denoise was running on the first.  Now I'm staring at a progress bar for 28s per image.

On 2025-06-20 my Lightroom Catalog-v13-3.lrcat file was 1,947,116BK.  After using the AI Denoiuse on just 262 photos by 2025-06-28 it had increased to 3,480,836KB.

I routinely backup every day after use so I can track the size of my catalog file and that much of an increase is not normal at all.

Hey Adobe,

I hope you are well!  Judging by the comments in the discussion board, there seem to be some kinks to work out with the Denoise tool in this latest release of Lightroom Classic (14.4)

My concern or suggestion rather, is for the tool to run in the background as the previous one did.  This allowed me to run a batch (say 50 photos within the current library), while continuing to preview and/or do other edits the following ones.  With this new release, I am stuck not being able to do anything while the denoise is applied.

Also, I have to say that I really liked the pop up interface in the previous version.  It allowed for one to preview the amount of Denoise to be applied, rather than applying the default (50) and then moving the slider to the desired amount.

I hope others agree that the previous version had an easier and more efficient workflow and perhaps it can be reverted or at least improved.  Thank you as always for a great product which makes our work way easier than "back in the day."