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christophe_7972
Participating Frequently
May 23, 2025
Answered

Preview building extremly slow (tested with Parallel builmding on and off)

  • May 23, 2025
  • 3 replies
  • 426 views

So, I looked around, seems more have this issue, even with more powerfull PCs.

 

I did a test, with the parallel building on and off. The difference in CPU usage? EXACTLY THE SAME!

I timed it twice, on and off, both times in 30 seconds, it only build about 20 previews in both cases.

Not seeing ANY difference with it on or off, seems its bugged. I would expect to see atleast some difference.

 

I have to build 4000 previews, this is insanly slow, I need to wait almost an hour to get them build. That's unworkable. It's a 12 core/24 thread CPU, which according to benches is faster then a desktop i7-12700K on multicore benches, which also should be a more then suffcient powerfull CPU.

I'm on windows btw, and its the latesest LR but has been always like that.

 

Lightroom Classic version: 14.3.1 [ 202505061331-b063faef ]
License: Creative Cloud
Language setting: en
Operating system: Windows 11 - Business Edition
Version: 11.0.26100
Application architecture: x64
System architecture: x64
Logical processor count: 24
Processor speed: 1,9GHz
SqLite Version: 3.36.0
CPU Utilisation: 31,0%
Power Source: Plugged In
Built-in memory: 31817,8 MB
Dedicated GPU memory used by Lightroom: 25,1MB / 7948,0MB (0%)
Real memory available to Lightroom: 31817,8 MB
Real memory used by Lightroom: 7392,0 MB (23,2%)
Virtual memory used by Lightroom: 7785,7 MB
GDI objects count: 975
USER objects count: 3428
Process handles count: 4172
Memory cache size: 8360,1MB
Internal Camera Raw version: 17.3.1 [ 2227 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 2645MB / 15908MB (16%)
Camera Raw real memory: 2707MB / 31817MB (8%)

Cache1:
NT- RAM:0,0MB, VRAM:0,0MB, Combined:0,0MB

Cache2:
m:8360,1MB, n:0,0MB

U-main: 93,0MB

System DPI setting: 120 DPI
Desktop composition enabled: Yes
Standard Preview Size: 3858 pixels
Displays: 1) 3840x2400, 2) 3840x2160
Input types: Multitouch: Yes, Integrated touch: Yes, Integrated pen: Yes, External touch: No, External pen: Yes, Keyboard: No

Graphics Processor Info:
DirectX: NVIDIA GeForce RTX 4070 Laptop GPU (32.0.15.6636)
Init State: GPU for Export supported by default
User Preference: GPU for Export enabled
Enable HDR in Library: OFF

 

 

Correct answer GoldingD
I have to build 4000 previews, this is insanly slow, I need to wait almost an hour to get them build.

Actually, in my experience, just a few hundred can take an hour or two. That is why, when on a photo trip, say for example to a National Park, I copy my day's photos to my laptop first, then start my import (via ADD option) with minimal preview creation and go out to dinner, when I return, they will be ready for editing. Typically, this a 200 to 300 images. So 4000? Yep that can hurt.

 

If you are not using the Add method, consider using that as to spread your import process into separate steps that hopefully can be managed better. Overall time for the complete workflow may not be less, but more tolerable. This is an import workflow used by some Landscape Photographers. One advantage is to get photos copied (copy, not move) from the memory card to a hard drive ASAP. Then, using the Add instead of Copy option, and likely with minimal preview creation, minimal presets, the catalog can be populated, then the previews created later, perhaps as a batch, or more likely as you cull thru the images.

3 replies

GoldingD
GoldingDCorrect answer
Legend
May 24, 2025
I have to build 4000 previews, this is insanly slow, I need to wait almost an hour to get them build.

Actually, in my experience, just a few hundred can take an hour or two. That is why, when on a photo trip, say for example to a National Park, I copy my day's photos to my laptop first, then start my import (via ADD option) with minimal preview creation and go out to dinner, when I return, they will be ready for editing. Typically, this a 200 to 300 images. So 4000? Yep that can hurt.

 

If you are not using the Add method, consider using that as to spread your import process into separate steps that hopefully can be managed better. Overall time for the complete workflow may not be less, but more tolerable. This is an import workflow used by some Landscape Photographers. One advantage is to get photos copied (copy, not move) from the memory card to a hard drive ASAP. Then, using the Add instead of Copy option, and likely with minimal preview creation, minimal presets, the catalog can be populated, then the previews created later, perhaps as a batch, or more likely as you cull thru the images.

    GoldingD
    GoldingD
    Legend
    May 24, 2025

    In the System Info you posted, the Library path is cut out. This might be important. Especially as you are using Windows and might have run into Microsoft's blasted OneDrive nuisance. (MACOS users will not have this issue, ever)

     

    This bit:

     

    Application folder: C:\Program Files\Adobe\Adobe Lightroom Classic
    Library Path: W:\Active Projects\Photography\test\test.lrcat  (if the words OneDrive are included in this, then that is bad)
    Settings Folder: C:\Users\DavidsLocal\AppData\Roaming\Adobe\Lightroom

     

      AxelMatt
      Community Expert
      AxelMattCommunity Expert
      Community Expert
      May 24, 2025

      You graphic device driver is outdated. Goto NVidia's site and search after the recent driver version. Download and install it and check again.

      If you have buldin a CPU with an internal graphic processor disable the processor internal graphic card.

      To disable  use the Device Manager on Windows. In the Device Manager, right-click the card's name and choose Disable.

      If this doesn't help try resetting the preferences of Lightroom Classic:  How to reset Lightroom Classic preferences (adobe.com)

      It's recommended to backup your preferences before you reset the preferences to the default settings: 

      https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html

       

       

       

       

       

      My System: Intel i7-8700K - 64GB RAM - NVidia Geforce RTX 3060 - Windows 11 Pro 25H2 -- LR-Classic 15 - Photoshop 27 - Nik Collection 8 - PureRAW 6 - Topaz Photo AI
      C
      christophe_7972Author
      Participating Frequently
      May 24, 2025

      This answer is invalid for this issue.

      1ste: on a laptop, you can NOT disabled this or it will break your graphics in windows

      2nd: the drivers I'm using are the latest stable ones, newer ones have issues and has nothing to do with this problem. As this issues is there for over a year... when this was the latest driver and was on the latest LR also back then.

      3th: GPU has nothing to do with building previews. Why? Because preview building is 100% CPU related! The Parallel generation option should assign more or less cores and speed up things or not. Which doesnt make a single difference.

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