DXO PhotoLab 6 running impossibly slowly on MacBook Pro

Testing PhotoLab 6 on my relatively new MacBook Pro.
Processor: 2 Ghz quad-core Intel Core i5.
Graphics: Intel Iris Plus Graphics 1536MB.
Memory: 16GB.
macOS Ventura 13.4.1
(6-month old laptop)

DXO PL6 ran fine for 5-6 days, but now it takes minutes to switch from one photo to another or to switch from PhotoLibrary to Customize. It will occasionally run normal-ish, but not for more than two or three photo edits.

What suggestions do you have to diagnose and treat this? It seems like my laptop is sufficient. Is there a gremlin or bug in my software or possibly on my machine?

Not an solution to your issue, but Apple discontinued Intel based laptops in December 2021, so I’m curious why you say your laptop is only 6 months old, they haven’t been produced for 20+ months.

I can see how a MacBook Pro could be only six months old that hadn’t been sold since 2021: it was purchased on closeout after being discontinued. Still this does make it a MacBook Pro that’s at least a couple years old at least in terms of models, which is what really counts.

Nonetheless PL6 should be doing better than this. People will complain about slow performance doing, specifically, noise reduction; then an upgraded video card may help, but this is much more general slow performance issue that I don’t think should occur on even a 2-4 year old MacBook Pro model like this one.

One thing to take a look at: what other apps are running in the background? One good way to see this is to click the Apple logo in the upper left and choose Force Quit. You can try closing out from there, say, half the apps running, or even all of them except PL6, and see if that makes any difference in your issue. If it does, add them back, one at a time to find the resource hog. Note that newer Apples aren’t as prone to this issue as Windows PCs but still, I’d check it. I found on my Windows PC using Adobe Lightroom Classic, that having my password manager running even only in the background from startup would cause problems like you’re reporting; it doesn’t cause an issue with PL6, but it does with LRC. If I not just close the password manager but exit out of it from Systray or Task Manager, similar to force quit in iOS terms, Lightroom runs fine. It can be one small app like that which is not playing well with PL6.

If that doesn’t help, the other thing I would try is uninstalling (from Finder > Applications) PL6, then download a new copy and reinstall it. This doesn’t count as an extra activation. Sometimes an app just gets borked and needs a fresh start.

You seem to be saying that it was performing fine and then it suddenly deteriorated. In that case, something must have changed. What was it - a new application installed or now running, running out of memory or SSD storage, much larger photos, are you now running it unplugged rather than plugged into the mains…? Are any other applications running slowly, or just PL6?

If you are now running it unplugged, go to System Settings (cog icon) and check the Battery Health and Energy Mode. Try changing the Energy Mode settings for On Battery and On Power Adaptor.

First shot, as you have probably tried already, is to shut down including a power off - not just a restart. Run the Activity Monitor to see how much GPU, CPU and memory the system is using. Is PL6 consuming the most, or is it something else? If it is something else, then close it.

If you have lots of tabs open in Safari, close them. Then close all the open applications.

Check how full your SSD is. If it is really crammed, then the system may be unable to swap tasks into and our of memory. Delete items from the bin and other locations if necessary.

Make sure that MacOS is up to date. Are you running any third party apps such as Clean My Mac? This application has a reputation (fairly or unfairly) for introducing vulnerabilities that can be exploited by malware.

I hope that helps.

Thanks. Have checked off most of these actions including:

  • Hard restart of the laptop.
  • Uninstall PL6 and reinstall.
  • MacOS is current.
  • Checked hard drive (3.5T available on a 5T drive)
  • Laptop is plugged in.
  • Activity monitor - PL6 eats .5GB to 4.8GB of RAM. So that seems like a lot. Dropped other RAM eaters (I think) but it still runs VERY slowly.)

I do have some backups running in the background, a relatively new action (i.e. Time Machine). Is that a potential culprit?

Thanks for your help so far.


P.S. As to the machine age: yes, it was clearly a unit purchased at the end of the model run, but should it be that much of a mismatch with PL6?

I would be surprised if the model of MacBook is the problem. I am running PL5 on a 2013 model desktop Mac and most of the time it is fine. You are having trouble with basic tasks, which should be quick.

It is good that you have tried all those diagnostics, but disappointing that none of them fixed it. Using 4.8GB of RAM should be OK, provided that you don’t have other processes that are using enough memory to take you over your 16GB. Even then, MacOs is supposed to be good at swapping processes into and out of real memory.

Time machine is designed to run in the background, so it should be at a lower priority than PL6. You could always eject your Time Machine disk in Finder and then unplug it to see if that makes a difference.

I would have a look at the CPU tab in Activity Monitor. You can click on the headers to sort processes in a particular order. Check the CPU utilisation to see which processes are consuming the most. On my desktop Mac, Microsoft Teams is consuming 13% of CPU even though I am not using it. On my MacBook, Mail was using 23% but only during its initial mail replication. Then click on %GPU to sort the GPU utilisation by process.

I hope that helps.

I have been using DXO for many years, probably a good 8 years, and had no problems running previous versions of Photo Lab (including before the name change) for years on a PC I built in 2011. I stopped using it the past few years because I stopped using my A7RII but recently installed Photolab 5 on my 1.5 year old MacBook Pro high spec (M3 Max, 64GB RAM, 12 cores) that cost about $4.5k and I find that when I have a project with a lot of photos (e.g. 700+ in my current one) the scrolling between photos is very laggy to the point where it’s extremely frustrating to use. Selecting/unselecting photos is also laggy. Didn’t happen when I was working on smaller projects (<100 photos). No issues though with previews, using the editing tools or processing the photos. Mostly it affects the scrolling and selecting/unselecting photos.

Supposedly PhotoLab is optimized for Apple silicon so not sure what the issue is. I have no problem working on Final Cut Pro X (the only other significantly memory using app I use) so I assume it’s a DXO PhotoLab issue. Hopefully this is a known issue and something DXO will try to work on as I still love PhotoLab more than Lightroom and the other big photo editing apps.

Hi Chan and welcome to the users’ forum. You have found the Achilles’ Heel(one of them) of Photolab. It’s been that way for years, you should have run into it before on your PC, with no relief(although I think that it is worse on macos. I’m on Windows.) You need to always use folders with <100 photos in them in order to get good speed from PL. Just think of it as a price you have to pay for the excellence of Photolab.

Hi Mark,

While some posters have indicated they have slowdowns in folders with very large numbers of files, in my experience limiting the number of files to less then 100 is unnecessary. While I don’t have any folders with 700 or more more files like @chancroid99, I do have many folders with 400+ raw files on my Windows 10 i7-6700 desktop and I am not seeing any performance issues. or slowness of any kind.


PL7.5, Win11, i7-14700KF, RTX 4070, 32GB RAM, 4TB M.2 SSD dedicated to photos, using PL 20GB preview cache.
No such problem here with 3000 photos in a folder, but it’s Win and PL7.
Maybe it’s some Local Adjustments that make it slow?
I’ve noticed that using a brush can produce very large DOP files and hence database entries.

For each “session” I create a new folder. Sessions range from 100 to 3,000 RAWs from 24MP camera. When PL opens a folder for the first time it takes some time to create new previews and database entries, so I have to be patient, but it’s not a big problem. Usually the first thing I do, is mark all photos and apply my preset - no problem with that either for 3000 raws. I rarely use LA, which sometimes caused slowdowns indeed, but not too dramatic.

It just took me 7 sec to open a “used” folder with 1300 RAWs previously edited (+1300 DOPs). No problem moving from photo to photo.

Opening a folder of 1270 RAW files in PhotoLab 7.5.1 on macOS 14.4.1 on a 5K 2019 iMac brought CPU load up to 500% for a minute or two, then load dropped to around 170%. Selecting one image after the other in rapid succession pushed load to just above 540%.

Memory load was about 700 MB max.

While DPL continued to index the folder and possibly calculated previews, the reactivity was in no way reduced that I’d felt something. Images displayed, e…g. falloff disappeared and the next image came up as I selected it with the arrow keys. Summary: No issue with a 1200 plus file folder.

Well, my iMac is not a quad core i5, but an 8 core i9 and the gPU a Radeon Pro 580X 8 GB, RAM is 40 GB and images are on the local SSD.

So, if performance unexpectedly drops, something must have changed, be it a silent macOS update (and consequential optimisation runs) or anything that might show in activity monitor. Best to check what’s going on in the Activity Monitor app.

Hi Mark and Wlodek. @mwsilvers and @Wlodek you guys are both working with top-notch equipment and I’m still using my almost 4 year old computer so I still have to limit my files per folder. @chancroid99 is in good shape too with a relatively new Mac, but I still think that the problem is worse on Mac than on the Windows version(I could be wrong about that though.). Thanks to you both for the interesting info.

But I have also i3 (2 cores), 16GB RAM laptop without dedicated graphics, definitely low-end, which I (rarely) use in the field for initial edits, mainly crops. The last time I used it was with 1500 photos and didn’t complain, but I don’t remember actual timings. I’ll test it tomorrow and let you know. If I remember correctly, some people with 64GB/Win11/i9 complained here about 100+ folders, so it looks like not only Mac problem. Strange.

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My Windows 10 i7-6700 chipset with 24gb ram is in a stock HP desktop which was purchased from Costco in New Jersey in 2016! That is eight years ago. It was unchanged from its original configuration until around 15 months ago when I added a GTX 1050ti card to improve DeepPRIME processing times. A few weeks ago I made some additional hardware upgrades to that machine, but even prior to those recent upgrades PhotoLab performance on this 2016 machine has always been stellar. Those recent upgrades included a new mother board, a new power supply, a new and larger SSD drive and an Nvidia RTX 4060 card. The chip set and memory was not replaced. and is far from top notch.


Thanks for all the replies everyone, it’s interesting and helpful to hear about other’s experiences.

I looked in my records and I first started using DXO in 2013 with Optics Pro 8 on a Core i7 quad core PC that I built a couple years before. I upgraded with each version over the years but there was about 4-5 years until this week that I might have upgraded (to some version of PhotoLab) but didn’t really use it much (I was working on a 2019 batch of RAWs in PL5 when this came up haha).

But with all the Optics Pro versions I would have many hundreds of RAWs in the folder and scrolling through them in the program never caused any slow down. Right now I started a new project with about 20 photos and there is not much lag, but frankly it’s not as smooth as it should be. I don’t think I have the patience to break up my large projects into smaller batches but I did find that there is zero lag when using the scroll bar (cumbersome to use though as the slider is very small), so I’ve been doing that for now.

I just hope that it’s a DXO issue that the devs could hopefully work on optimizing because coming back to PL was so easy, everything works the same, everything I want to do is easy to do unlike in Lightroom or the other programs I’ve tried, and it’s amazingly still not following a subscription model.

UPDATE: So I decided to upgrade to PL7 (from PL5) to see if it might improve things (and to support DXO as PL5 otherwise has everything I need) and incredibly it does! I actually had deleted my 700+ RAW project after I exported all the JPGs and the largest folder I have currently is 400+ (I didn’t want to combine folders and stuff just to test it) and there is zero lag when scrolling the thumbnails in the program now in the Customize view. I wonder if PL5 was not optimized for Apple silicon (my MBP is a 2023 M3 Max)? Who knows, but problem seemingly solved for now so happy days again. Thanks y’all!

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Scrolling with the bar and selecting images one after another are quite different things imo. Using the scrollbar leaves the selected image alone, while scrolling with arrow keys changes the selection, which triggers DPL do do something. Note, as of now, this is just a guess, I’ll check it when I’m back at my Mac.

In PL5, the scrolling I was doing on my MBP was with the touchpad, moving left and right on the line of thumbnails on the bottom of the Customize view. Does that still select each photo as you move/hover over and past it? I can see what you mean about the scroll bar bypassing that. All I know if that PL7 solved the lag for me so would recommend upgrading for anyone with a similar scroll lag problem using a newer MacBook.

It appears that they have quietly fixed that old(at least going back to PL 3) problem. In truth, I have been working on small folders of photos for years and haven’t tried a large batch for years until today. What a great new feature without an update! Thanks to @mwsilvers, @chancroid99 , @Wlodek and @platypus for updating my information.

I did a test with 3000 fresh photos on i3-10110U. It worked but I had to be patient with selection and thumbnail generation. After PL updated its database and cache, editing went smoothly. Going to next photo required about 2 seconds for preview generation (as expected) but revisiting the photo was fast.

If PL opens a new folder, it generates thumbnails in the background for all raws in the directory. Generating thumbnails takes almost as much time, as export to jpeg with simplified corrections, so for 3000 raws it’s a long process. I wait for this process to finish before I switch to ‘Customize’ tab (monitoring CPU and disk).

If you select all files in the filmstrip (Ctrl-A on Windows), PL does some very intensive database operations, so on a fresh folder it may take very long before you see all thumbnails selected. Maybe DxO should tune it - I’ll ask them about it if I find time. My main database is just over 1GB with 50k raws and 50k jpegs.

Applying a preset to all selected photos causes PL to regenerate thumbnails in its cache, so again it’s a long process in the background. I prefer to wait for PL to finish it, before starting edits. Note that previews are not generated at this stage (at least in PL7.5/Win).

While moving from photo to photo in the preview window, preview jpegs are generated and stored in the cache, if the preview is not there or is outdated. It may take half a second or several seconds, depending on hardware.

The background thumbnail generation is limited in config to 3 ‘tasks’ running in parallel but probably each task can also run some small subtasks in parallel. I’ll ask DxO support if we may touch this parameter to tune it for CPUs with many cores.

On Macs it might be a very different story.

So your advice on limiting folder contents is based on the age of your equipment…

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