DxO Photolab 4 is using all of my RAM


Today I purchased PL 4 and after a couple of hours editing, my iMac essentially becomes unresponsive because PL is consuming all of the available RAM (I have 40GB installed, 2x4 + 2x16). It’s crazy! I’ve never seen any application do this before. My Mac is even using swap. Seems like there’s something wrong.

Anyone familiar with this issue?

  • Jasper

Cannot help re PL4 but have been running PL3 since launch and have never seen that on my iMac (32 gig).

Hi Jasper,

I f it was the first launch of PL4 and if you have a lot of files in folder, PL should make some initiating jobs, like indexing files, applying default preset, …

You could stop PL and relaunch and then having better RAM usage.

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@JPDW how any files do you have that you want PL to manage?


The first time I launched PhotoLab 4 (after deleting the database imported from PhotoLab 3, for other reasons), I had a similar problem but related to disk space.

PhotoLab’s database transaction logs grew several GB while indexing image folders, filling up all of the disk space. As my SSD is not very big, I had to go over it several times.

However, after this first task is complete, everything works normally and the transaction logs, although large at times, do not fill the entire disk.


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Please post the full path to the transaction log. I’d like to check what its size is. Why? I’ve never seen huge files in connection to PhotoLab. Therefore, I’d like to check if I’m missing something.


This file is located alongside the database in ~/Library/DxO\ PhotoLab\ v4/DOPDatabaseV4.dopdata-wal (macOS). At this time, mine is 12 MB (PhotoLab is off). Its size varies when using PhotoLab but it’s still reasonable. The only time I saw it grow disproportionately was indexing large directories.


okay, I see it. Never had an issue with it though. I mostly use DPL for select images, so the total file size stays reasonable. My main photo app (Lr) has a previews object (it looks like a file but is actually a folder) that currently contains 60GB.

I now let DPL index my photo collection and see what the final file size does: it grows during indexing, when I quit DPL, the size of the …-wal file is “0” afterwards.

I can see that the way DPL works, it can fill up the drive under certain conditions.

A .wal file (or -wal file in MySQL) is a write-ahead log file. It is used to accumulate the actual DB writes in a log prior to actually committing them. This is similar to the journaling filesystem format used on Macs; in the event of a crash or interruption, the DB can be restored to the prior state, and the accumulated writes will be applied.

Once PL3/PL4 quits, the -wal file would be expected to have a zero size

This is what I see on my Mac. On the other hand, the original poster noted that RAM was completely consumed.

Neither RAM nor drive space should be consumed to an extent that compromises the whole system. If it happens anyway, there might be an issue in either the app or the OS.

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That’s right. I suspect the behavior depends on the capabilities of the machine and the number of files to be indexed.

When my WAL file grew disproportionately, the RAM usage went up too. It arrived around 6 GB for PhotoLab. At this time my SSD was full (0 bytes available) and my Mac froze. In addition, the folders to be indexed contained “only” 3,000 to 4,000 files each. What would have happened if my disk had had more space or if the folders had contained more files?

On the other hand, it is curious that PhotoLab can use almost 40 GB… There is still a problem.


Indeed. Either macOS does not provide proper resource management or DPL does not use it (correctly). Exceeding resources seems like a beginner’s mistake :zipper_mouth_face:

Quiting and relaunching seems to help. Quite stable now, wondering what happenend before. Thanks.

Not that many actually, just a first project to start with. Have many other files that I wanted to copy to the same folder, but now I’ve seen what it can do to the application and the iMac, I’ll try to change my workflow a bit to avoid having PL (re-)index everything

Hmm, I haven’t noticed my available disk space being occopied by PL files. It just seems to be a RAM issue.

Just a quick snap from my screen…

Bildschirmfoto 2020-12-02 um 21.39.04

PL is correspondingly responsive, i.e. dead slow.

How long does it take to get your RAM usage so high? What is DPL doing during this time?

10 to 15 minutes. Opening a directory with RAW files and rendering thumbnails.

How long does it take to get your RAM usage so high? What is DPL doing during this time?

I took just over two hours to reach the RAM ceiling so to speak. After creating a few projects and importing several hundreds of photos, I started editing and exporting untill the iMac basically froze.

Yeah, the first time I had PL4 index a folder with 100K+ images, the drive’s several hundred GB of free space was completely filled up and the process stalled. I rebooted, relaunched, and restarted the indexing process, and all’s been smooth since. This was on my 2013 Mac Pro running 10.15.7.