Opening a Detail view (until I can edit, move sliders, etc..) can take 30 seconds

Report · Nov 13, 2025

I have a problem. Lightroom (not Classic) runs incredibly slow on my MBP with M4 and 16GB ram.

How slow?

Opening a Detail view (until I can edit, move sliders, etc..) can take 30 seconds.
After opening a folder, I can't change star rating for 20 - 30s.
Copying Edit Settings can take around 30 seconds (1 photo).
AI edits like Denoise take between 1 and 2 minutes per photo.
Exporting 10 photos take 10 minutes.

No even mentioning minor hiccups like lags when moving sliders etc. All in all, it's unuseable.

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Few more details:

- All photos are stored locally on the system SSD.

- More than 150 GB free on the SSD

- All photos are 61MP uncompressed RAW, with ~80 photos per folder.

- More edited photos in the folder result in even slower operation.

- LR cache allowed to use max. size

- The app is updated.

- MacOS is updated.

- GPU setting in LR: Auto (but same issue when on / off)

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System info:

Lightroom version: 9.0 arm64 [ 20251017-1944-414afc8 ] (Oct 17 2025)
NGL Version: 1.42.0.5
WF Version: 8.0 58cbd19
VF Version: 1.0.164
HIL Version: 40501
CAI Version: c2pa-c/0.6.0 c2pa-rs/0.46.0
PH Version: 5.2.3
Adobe GSDK Version: 1.4.0.42
CR Version: 29.5.0.202509162212_6e7a997

Operating system: macOS
OS Version: macOS 26.0.1 (25A362)
Application architecture: arm64
Computer model: Mac16,1 / Apple M4
Logical processor count: 10
Real memory available to Lightroom: 16.384,0 MB
Real memory used by Lightroom: 2.470,0 MB (15,0%)
Peak memory used by Lightroom: 4.164,0 MB
Memory cache size: 3.472,8 MB

Internal Camera Raw version: 18.0 [ 2389 ]
Maximum thread count used by Camera Raw: 6
Camera Raw SIMD optimization: Neon
Camera Raw virtual memory: 1284MB / 6144MB (20%)

Display: 3024x1964

Graphics Processor Info: Metal: Apple M4
Graphics Processor Detail: loaded: Yes, supported: Yes, compute: Yes, init: I4_GPU4, hard: success, soft: success, al: Yes, dl: No
OS Media Capability: true

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Is there a fix for this? Photoshop runs without issues, but LR is a pain..

Report · Nov 13, 2025

Hi there! I'm sorry to hear that you're having trouble with Lightroom. Could you please let me know if this issue has just started or if it's been ongoing for a while? In the meantime, here are some steps you can try that might help improve the situation.

1) Clear Camera RAW cache: In Lightroom's Preferences > Cache and click on Clear Cache.

2) Try setting your GPU performance mode to High: In Lightroom's Preferences > Performance > Select 'High Performance' for Graphics Performance.

3) Delete the AI Model Cache: Go to Finder, User > (Command + Alt) to find the hidden Library > Application Support > Adobe > CameraRaw > ModelZoo. Delete the entire contents of the ModelZoo folder. This should help with Denoise performance.

4) Delete the Camera Raw GPU config file: User > (Command + Alt) to find the hidden Library > Application Support > Adobe > CameraRaw > GPU > Adobe Lightroom > delete file Camera Raw GPU Config.text. Perform steps 3 and 4 in succession, then restart Lightroom.

5) Try resetting your preferences: When starting Lightroom, hold down the Option key and the Shift key. Lightroom will start completely reset to the default after you confirm that you want to reset preferences.

Let us know how it goes!

Please use @ before mentioning my username so that I can be notified ASAP.

Noel

Report · Nov 24, 2025

Hello @Noel Orridge,
Thank you for your response. Here are my comments:

0) It is like this since I installed LR on this MacBook.

1) Tried several times. Zero improvement.

2) There is no such option as "High" performance mode. I can choose from Auto, Off, or Custom (under custom, there is no "High" option either).

3) and 4) done. No improvement at all after reinstalling Lightroom

5) Done (now and before). No improvement.

6) In case you ask - yes, I updated and reinstalled LR multiple times.

I'm trying to export 32 photos now from Lightroom. After 42 minutes, there are 7 exported.

Adobe has to finally do something. Many people buy M4 MacBook to use it with tools like Lightroom, and there is no warning when paying for subscription that it's a tragedy show on such setup.

Report · Nov 27, 2025

Hi @magenta_6247! Thank you for trying out the steps above. I appreciate the effort! It's unfortunate that nothing has worked so far, but fortunately, we still have a few more troubleshooting steps to try out.

Quit Lightroom completely and open Finder and navigate to your Pictures folder. Locate the file named Lightroom Library.lrlibrary. Rename this file to Lightroom Library OLD.lrlibrary and restart Lightroom.
Delete the Camera Raw cache. Go to ~/Library/Caches/Adobe Camera Raw/ and delete that folder.
In Lightroom > Preferences > Performance. Use the "Custom" option for Use Graphics Processor and check "Use GPU for image processing".
If the above steps don't work. Try uninstalling Lightroom, but this time use the Adobe CC Cleaner tool. Here's how you download and run it: https://adobe.ly/486sotM.

Hope this helps!

Noel