Photolab 5 and memory usage

Just switch from PL3 to PL5 on my Mac M1 8gb of memory.
PL3 was already a big user of memory but now PL5 is HUGE !!
6Gb when opening and now 8Gb… Is it normal ?

I can’t speak to how PL5 uses memory on a Mac, but generally speaking 8gb of ram is insufficient for image processing.


The M1 Macs do treat memory differently so it maybe that the “old” rules do not apply as regards to ram. I run an M1 too but with 16 gig ram - I took the view more is better as a precautionary measure.

I am seeing PL5 starting at over 2GB but increasing to over 8GB memory on my 16GB M1 Mac Mini, working in a folder containing several hundred images. It slows down as I export images and I end up closing and re-opening it every 50 images to maintain UI responsiveness.

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I’m not seeing that but our usage may differ. If there is an issue out there though I won’t upgrade.

The amount of memory used seems to depend on how many images are in the current folder, as you would expect. It does go down sometimes, but moving to different folders makes it grow more than it reduces. In the end, I suspect they will find that some part of PL is not releasing memory as it should, and perhaps this is particularly noticeable on M1 Macs.

I’m happy to have upgraded anyway - it’s manageable for now, and much faster than PL4 was in my experience.

Thanks for all your feedback but… I can see that it might easily jump to 16Gb, I am at 12 at the moment, this means that even with 16Gb there will be a lot of swap…

This has been the same for years. The advice has always been and still is - don’t do that - try to split your folder into smaller sub-folders.

…which is why the issue should be addressed and not swept under the carpet!

Edit: DxO Support got me to try running PL5 with a new user. This deferred the UI slowdown until PL5 reached around 12GB memory used, so I have uninstalled some apps that had background processes running in my main user, and it does seem to help. Simply separating images into subfolders doesn’t really help (unlike with PL4 on an Intel Mac), because PL5 still consumes more memory as I open each folder, and doesn’t seem to release it when I move on to the next, on this M1 Mac.


I remember well what we could do with 1Gb of memory…
A process of 12Gb is using more memory than all my photo on the main folder & sub folder hard disk opened. Crazy.

Indeed - or 1 MB, before that! But if we have all that memory, it’s good to see PL using it well - it makes the UI faster for us in spite of the increasing size of the images we work with - so long as it also releases memory it no longer needs (which seems to be its problem on my M1 Mac Mini, but there may be other underlying issues), and plays nicely with other apps, which it does, even when it is itself no longer responding well. Diagnostic data has been sent for DxO Support.

DxO PL5 unusable on an M1Pro - more than 16GB of memory required …

I am using DxO PL since 2006 (Optics Pro at that time). Recently I upgraded to PL5 and tried it on a new MacBook Pro M1Pro with 16GB. Activity Monitor reports 3GB memory usage for the App alone plus 2-3GB for each simultaneous processed image (set to only 4). While processing D750 RAW images (24MP) PL5 uses all 16GB of available memory and swaps about 3GB to SSD - and finally crashes after some time - ridiculous.

Someone may say that one could further reduce the number of simultaneous processed images - but then DxO would not use the full processing power of the M1Pro anymore.

I would strongly recommend to look into this memory issue as DxO PL5 would appear to be not usable in production on an M1Pro Mac with 16GB of Shared Memeory. Part of the issue may be related by running non-native through Rosetta2.

Besides fixing the memory issue - DxO should release a truly native version for Apple Silicon Macs (universal app) as soon as possible as a free update at least for all owners of PL5.


I originally posted the text below in a different thread, but it is totally relavent here too so reposting it:

Hmmm, I just did a quick Google and there has been some news on Mac memory issues causing performance problems very recently. So whilst there are likely to be optimisations and improvements that DxO can make to Photolab (always welcome), there may also be something Apple needs to investigate too.


Replace “generally” with “historically”. I’ve had no issues running LRC and PL4 on my entry-level M1 MacBook Air with 8GB RAM. I digiteched a 5-day studio portrait shoot, using LRC to import, cull, batch apply WB, tweak exposures, then back up to two more drives, working nonstop through 8-hour days. It never even got warm.
That said, PL5 is generating “out of memory” messages on my M1 mini with 16GB RAM when doing batch exports of around 400 images or more. There’s a lot of talk lately about memory leaks on Macs, so this may not be limited to PL5, but I’ve experienced it only with PL5. PL5 grabs about 6GB or RAM, which is not a problem, but as the batch runs, Activity Monitor shows “Compressed” memory slowly growing until it reaches around 8GB and the error message pops up, forcing me to quit or force quit PL5 and relaunch it to start batch processing where it left off.


“This has been the same for years. The advice has always been and still is - don’t do that - try to split your folder into smaller sub-folders.”

I’ve never had this issue with PL4, even on my 2017 13" MacBook Pro with 8GB RAM.

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I might be in Apple side, but then, why is it specific to photolab 5 ?
No issue with Photolab 3

I’m using pl5 on a new mbp 14 with 64 gb of memory and getting the same issues. I ran a batch of 1500 files with 4 images processing at once. At first each processing thread uses about 2 gb. Over the next hour or that rises to 4 gb and then eventually 16 gb (this is each - not total) and the computer gripes about a lack of memory.

I was previously throwing any size batch in pl2-4 with my late 2019 mbp 16 with 32 gb of memory with zero issues. Still troubleshooting but it’s disappointing to say the least.

Been using dxo since mid 2000’s and am a fan so hope they sort this out.