RAM usage on Apple Silicon

[Bondi Blue]

There is strange behavior regarding RAM usage in Lightroom (Classic) on the Apple M1 and probably also M2 chips.
RAM usage is very acceptable (< 4 GB) when I start editing. After some edits on 24 megapixel files (no hdr or panorama) it grows to + 20 GB and macOS starts swapping. After a pause, I do a simple edit (in the basic panel) and it goes further up to 23 GB.
I can do edits with RAM usage below 4 GB when LR just started and after a while it needs more than 23 GB do do a simple edit. It appears that Lightroom is not releasing the RAM that is no longer needed (quickly enough). For the moment, I only use GPU for display because it's much worse when GPU is on auto or used for image processing and export. I'm wondering if LR sometimes forgets to release RAM used by the GPU...
I'm using version 12.5 on macOS Ventura 13.6 on 2 MacBook Pro M1 Pro's (16 GB and 32 GB). I had the same problems on earlier 12.x versions and on previous macOS versions.

[Conrad C]

What is the Memory Pressure at the time Unified Memory usage appears to rise dramatically?

Do you see an actual decrease in performance, or just that the memory numbers change a lot?

[Bondi Blue]

Memory pressure is orange.

When editing (only Lightroom is open) a small catalog (232 24mp photo's already imported and with generated previews for a 2560 x 1440 screen) the memory usage (Lightroom) is constantly increasing. There is sometimes a little drop (Lightroom does release memory sometimes) but not enough to avoid swapping at a certain point.
I can notice it when I open Photoshop. If I do that when LR memory use is low, it's faster.
If Lightroom alone uses more than the available RAM at a certain point, there is a problem if you want to open another application. If there is no other option for Lightroom then it is what it is, but I suspect it can be done differently.

You can argue that Lightroom caches data in memory to make it faster but it's the opposit. I now make the habbit to restart LR once in a while to relase the memory.
When I start Lightroom and I go from photo 1 to photo 232 (the last one), one by one in the develop module (without editing), RAM usage is low and does not increase. That makes me think that LR doesn't cache previews in RAM.
RAM usage starts to increase with simple edits. I understand that e.g. building a sky mask needs memory but why is that memory usage accumulated when I'm working on a different photo? I also understand that today is not 2003 when Photoshop 7 could run on a 128 MB machine but do we need a 64 GB machine to run LR and PS to edit 24 mp photos (without many layers)?

Swapping is a good thing when needed but not when it can be avoided. Swapping on the Apple silicon machines is fast thanks to the fast SSD's. A lot of people are using 8 GB Macbook Air or Mac Mini computers that are swapping a lot and people probably don't know.

I'm also using Capture One and memory usage is always below 8 GB when editing. To be fair, a couple of updates ago, they had an update that caused excessive memory consumption.

[Ian Lyons]

Memory, which includes caching is largely handled by macOS. M1/M2 Macs use unified memory shared between to CPU and GPU, but tends not to restrict the amount that the GPU can access. With apps such as LrC, which uses the GPU a lot in the Develop module, then a lot of memory is used for caching GPU related tasks. You can easily see how memory is being allocated by checking the Memory Pressure graph/table in Activity Monitor. I've attached a screenshot that shows how little of the memory used is allocated to LrC compared to the overall memory use after editing 50 30MP files. If you're seeing LrC using more memory than is physically installed, then we need to establish why. A screenshot of your Activity Monitor would be helpful.

What do you mean by simple edits? Be specific!

How many images have you edited when memory becomes a problem?

[Ian Lyons]

A copy of your 'System Info' would also be helpful. You can obtain same from the LrC Help > System Info menu item. The dialog has Copy button to capture the info, which you can then Paste into a forum reply.

[rtee13]

I recently bought a mac mini M2 Pro 32GB Ram 1TB SSD, and have this same issue!!  Very frustrating indeed!

It starts off using very little memory, then gradually increases to maxing out my machine!  I have to keep closing LR classic to reset the ram!!  Why is it doing this?  My previous 2017 imac27 i7 never had this issue.

Come on Adobe, please fix this.  My super fast machine stops feeling super fast!!

[Nizar33224150n75d]

Same issue here. I wish Adobe gives this topic a high priority

[mkrvsky]

WOW! It's defiantly terrible. I now how happy you were with the new 32GB computer and did not expect that the memory would be completely used, and the SWAP would be 25GB+!!!
I perfectly understand your feelings when I switched from MBP 13 M1 8/256 to MBP 14 M1 Pro 16/512.
This is a old problem from first M1, but Adobe does not give a damn about users.

[mkrvsky]

Have you been able to solve this problem? Many people have a similar situation. Thanks!

[Ian Lyons]

Please provide a copy of your 'System Info' as found under LrC > Help menu item. It would also be helpful if you provided a screenshot showing the Activity Monitor Memory tab as shown above in my post from 27 September 23

[mkrvsky]

Friend, thanks for your help! Make for you ActMonitor at eng lang)) 
This is practically a cold launch of the Lightroom.
Usually, after 1-2 hours of working with raw 30mpx Canon R, the swap file starts to be 4-6 GB.

[mkrvsky]