Photos app slow on MacBook Pro 2019 running macOS Sequoia 15.3.1

Replying to myself, it seems that the slowdown and memory leak is fixed under macOS 15.4.1 on my computer.

I don’t have to wait a long time to edit a

photo and restart Photos app after editing 3 or 4 photos :)

I notice the problem exists in the latest MacOS.

I did some tests, Photos are very big size, from a 60 Mega Pixel Sony camera.

I open an "Activity Monitor", search all "photo" processes, sort by CPU

Using "Photos" App to browse the photos imported from the Sony camera,

here are the result.

Format -- RAW, level 1 compressed

Size -- around 80MB

Response time -- less than 1 second

CPU Loading -- minimum

Format -- HEIC

Size -- around 30MB

Response time -- around 3 seconds

CPU Loading -- 70% to 100%

Format -- JPEG

Size -- around 30MB

Response time -- around 10 seconds

CPU Loading -- over 100% (multi-threading)

I notice the slow problem related to CPU loading, likely related to de-compress the photos.

RAW one, the decompression is much less.

HEIC, the decompression is more efficient.

JPEG, the decompression is most inefficient.

Small photo size (less than 8MB), the 'slow' problem is insignificant.

I think Apple mobile devices, HEIC will be standard.

iOS and MacOS, the latest 2 versions started supporting RAW formats natively from third party vendors.

HEIC has advantages over JPEG, especially for high resolution photos.

wrote: …Here it is with jpegs from a Sony A7 camera. … I would say a jpg is a jpg..

Here's the interesting thing:

I used the app GraphicConverter to make new jpgs from my Nikon jpgs, using 100% quality. I got files that are just about the same size as the originals, maybe 3% larger, in fact. The thing is-- these files load into Photos edit modes immediately, no delay!

I'm beginning to wonder what Nikon puts into those jpgs! I also wonder why I hadn't seen this until recently. It's hard to believe that Nikon has changed the files from a few months ago, especially since I don't think I've transferred updates from them to my camera. But then, I'm seeing it in Sonoma, as well. So weird…

Background: A jpg is a lossy compression, and the final size of the file depends on the way it is compressed. When I export jpgs from Lightroom, I choose 100% quality, which I assume (but am not sure) means lossless. But that's a pretty unusual choice. In Photos, you can export your pictures at different "qualities," and sizes"

They don't attach numbers, but since I don't know what the numbers mean, it doesn't really matter. File size can be made smaller by removing details and variations that the eye wouldn't notice, anyway. What we notice depends a lot on how big the picture is and how closely we look at it.

Since my GraphicConverter conversion produces slightly larger files, it seems unlikely that removed information in them. Most peculiar…

I'm using an M3pro MacBook, and Photos is very slow to load pictures for editing and cropping. It would be worthwhile to let Apple know

Feedback - Photos - Apple

I'll go there, again…

My MacBook Pro 2019 is also very slow, even with an 2T internal SSD. The upgrade to macOS 15.3.2 did not help to make things better. Photos is much faster on my MacBook Air from 2022 with Apple Silicon M2. macOS 15 Sequoia has been designed with Apple Silicon in mind and to take the advantage of the new processor models for the best support of artificial intelligence algorithms. I guess we are experiencing the difference between Intel processors and the new Apple Silicon processors.

hopjesvla wrote: "But of course, they know to mess up again"

I'm not sure who "they" are, but this is not a mess-up. It's what we expect from a revised database. New versions have information beyond what older versions understand. So the only way to transfer a newer Library version to an older one is through iCloud. I can use my iCloud Photos Library from Sequoia and from Sonoma equally well, since the sync together through iCloud.

Again, my experience is that Sonoma is also is a bit slower than I remember. And, for me, it clears up if I convert the jpgs from my Nikon to 100% jpgs with GraphicConverter-- indicating that the problem is really with the Nikon jpgs, themselves.

Photos is a bit faster on my M1 MacAir running Sonoma than on my M3 pro MacBook. The actual editing seems at normal speed, but each picture must be loaded in a process that seems just like loading from iCloud, with the little filling circle-- but I don't use Optimize, and it's the same for a not-System Library. It's just the same on the M1 MacAir with Sonoma-- maybe slightly faster. Once a picture is "loaded," it may well happen again-- it doesn't stay loaded.

Just now playing, I notice that I see this with Nikon jpgs, which range from 20MB to 40MB in size, and it takes maybe 4 or 5 seconds to load. A jpg exported from editing a NEF (raw) file in Lightroom, 45MB, seems not to require this loading time. Nikon jpgs, edited and cropped in Photos, take just as long to load as Nikon jpgs fresh from the camera.

Well, drat! I wonder what this means…

hopjesvla wrote: i hadn't got the problem on Sonoma, nor did the Sony had a firmware update in between so i can only point it to the Sequoia upgrade here.

I didn't have that problem in Sonoma, either, and I don't remember it when I first upgraded to Sequoia. But when I go back and use a Sonoma machine now, I see a form of the same behavior I'm seeing in Sequoia. And I don't see the problem at all with jpgs from other than my camera.

I don't usually re-format my memory cards until they fill up. I don't remember when I did that last (and I don't have backups with me that might tell me,) but I'm tempted to think that might be it. I'm pretty sure that I formatted the cards in-camera-- maybe I should try to format them with the Mac, instead.

I experienced the same thing on an iMac Pro.

I wanted to downgrade to Sonoma, but didn't find a way to create an APFS bootable drive with Sonoma installer on it. Time Machine option didn't work too.

Please, Apple fix this issue on next update!

I can't say that I've seen this issue on my MacBook Pro 2021 (M1) or my slightly older iMac (i9), both running Sequoia 15.3.1 (now 15.3.2) with the same large library. That's not to say that you aren't seeing problems, just that the slowdown is not universal to 15.3.x. Look for a compounding trigger.

Feedback sent.

The most amazing thing is that I wasn’t able to downgrade to Sonoma.