Photography - Lightroom Classic CC Performance Issues

Hi everyone,
It seems like there are quite a few photographers in the group so I thought this topic could be of some interest. I also thought I could get better help from the MPU gang. :slight_smile:

I use Creative Cloud Lightroom Classic to manage and process all my pictures. I shoot in RAW. I always thought LR struggled on my MAC. Mainly when using the brushes and simply while scrolling though my pictures!

So I waited patiently for the new iMacs and pounced when it came out (like Katie and Dave buying an iPhone). I bought the following

iMac (Retina 5K, 27-inch, 2017)
4.2 GHz Intel Core i7
32 GB 2400 MHz DDR4
Radeon Pro 580 8192 MB

But the struggling never really ceased. It was a bit of a disappointment. After trying everything I could find on the internet, I concluded that it was the software itself. It seems to be the consensus out there. I was considering an iMac Pro but because of the so-so improvement with my current iMac (above) I’m weary to plunk that much money without being sure.

Anybody feels he/she has good performance? If so, what’s your secret?

I already tried many suggested things:

  1. GPU performance ON and OFF
  2. Increase cache size
  3. Run from small photos catalog
  4. Run with catalog on local SSD

I even use a Thunderbolt 3 enclosure with 3 SSDs in RAID 0 to hold my photos. >500MB/s reading and writing. But my active years are on my local SSD.

I’m covered with backups… the only place I’m not backing up to is a satellite orbiting the earth :slight_smile:


I have pretty much the iMac as you, and while my use of Lightroom has reduced a bit, I do think performance is pretty good now, especially after the couple of most recent performance releases.

I run the most recent years off my internal SSD along with the LR catalog. Of course, I wish it could render even faster, but I feel that the current performance is significantly better than a few years ago.

Suggest you check how your system performs with JPGs of the same resolution just to get a feel for the difference. Not suggesting that you switch to JPG, but non-destructive RAW editing is still quite a resource intensive task.

Ok. Sounds like I’m just impatient. :slight_smile:

Thanks for the feedback! I’ll try that.

You are correct. Processing jpg of the same size is much smoother. Must be the RAW editing.

Thanks again.

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Actually, I will comment that I too have been disappointed LRs performance of late.

I recently switched from a “trash can” MacPro (2013), which I sold, to editing on my 2016 13” Touchbar MacBookPro, 16 GB ram. I was surprised to see how sluggish the latest LR runs. Admittedly I am editing huge files (Nikon D850 raw files), but stil…

I have been looking at both Skylum and OnOne as alternatives, but right now I lack the time to spend learning a new platform as well as I know LR, and neither yet has reached the level of cataloging that LR provides. I am waiting to see what the advertised upcoming release of Skykum, claimed to offer a new DAM workflow, will bring.

I was actually considering trying out an eGPU, but I cannot find any good real world reports to convince me this will be the solution to LRs sluggishness.

Definitely, huge RAW files are a big toll on LR. I also look at alternative but I’m in the same boat as you. Precious time to move to another platform as to be worth it.

Thanks for chiming in.

I have an entry-level iMac Pro. It also feels on the slow side with Lightroom. That’s one thing that I miss about Aperture. It flies on this machine. Unfortunately Aperture has gotten to be too unstable to trust. Lightroom usually does a better job on many adjustments anyway so I just try to develop patience. Sometimes it works.

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I’m using the new iMac with just the i5 processor, but the same Radeon processor with the 8 Gbyte memory. Changing my photos in Adobe RAW and Photoshop is very fast.
Perhaps these features have a break in Lightroom? They perhaps put everything in the RAW and Photoshop programms so these run as fast?

Just once try to correct or improve your pictures with this combination. See if it goes faster.

I’m Running LR on a 2013 iMac and don’t run into any problems BUT I don’t have much in the way of RAW files to edit and in fact I don’t do much editing in LR yet at all.

I primarily use the extensive cataloging features and for that task it’s fine. Files are on our RAID server, catalog and thumbnails on my internal hard drive.

Newer versions seem to be a lot speedier than older ones when doing imports, probably my biggest task at the moment.

Hi Harrie,
Not sure the steps you are proposing. I edit my pictures in LR in RAW format. Are you suggesting to use Adobe RAW editor and then Photoshop?. Not use LR?


Hi Oogie,
Yes, from @airwhale test, I definitely can pinpoint the problem to be the intensive cpu requirement to edit RAW files. I too like the cataloging features of LR. I like that I can find my pictures in a tree of directories on my drive as opposed to a blackbox database.

Thanks for the feedback.

I still got an iMac in a quite similar configuration. There was a period several LR updates before where I was close (7.?) to delete. Performance was terrible. I contact Adobe and they guide my to reinstall the app. This helps and with the latest updates it works much better. Parallel I try On1 Photo RAW, this is much faster and with the current update last week it still speeds up some more. It is a good alternative but I’m still not sure if I can live without LR…

I use Lightroom Classic on a 2016 MacBook Pro with touch bar (i7 2,7Ghz - 16gb ram - Radeon Pro 455 2GB) and everything is quite smooth (editing Canon 5DMKIII and Fuji XT2 raws - and even 1000+ Nikon D750 raws in the last month with a friend).

I guess that performance is quite a subjective matter, it depends on what you do and what you think is slow or fast, if I can explain myself.

Anyway, LR has never been good at brushing (even tho it has got way better with latest updates) and it is the most demanding task it does; and scrolling large amounts of thumbnails can be quite demanding too, if it needs to render a lot of them: you might have better luck if you wait some time (30 seconds or so) after opening a folder of pictures

There is an option to use SmartPreviews to edit pictures which makes everything run much faster. There is a bit a precision losses but I could not notice it. I always thought the smartpreview option was for allowing small file editing on a another machine without bringing the RAW files. Turns out, you can speed up significantly editing of RAW files with this option checked up. It is in Preference>Performance mid page.

Thanks everybody for chiming in, It’s a pleasure being part of this group. And I can say, I like the new interface!

That is what I mean. I tried to use Lightroom, but I thought it was more specialized in arranging the pictures in good folders and renaming in batch and less to edit them. Because I put al pictures of one event in one folder, even when I use more camera’s and only edit pictures who need any change I only change pictures in Photoshop. When you click on a RAW picture in Bridge, it immediately opens in RAW. There you can do the changes, when needed like color saturation or lens corrections. These changes can be copied and pasted to a part or all other files. When you are ready in RAW, you click open and Photoshop will be opened. There you can do lots of changes and crop, but you also can save the picture in most known formats. Don’t think I’m a pro. I’m an amateur photographer asked for events like 10 times each year. My pictures are published in magazines, but it is not my living. As a retired technician I just enjoy my hobby and use Adobe Photoshop CC on my Mac, iPad and iPhone.

Excellent. I understand. I’ll give it a trial. Thanks for your help!

I do need toads a new experience I just found.
My iMac has an 500 GB SSD and I put an 250 GB Samsung SSD in a USB casing. With an USB 3 to Thunderbold 3 connector I hooked this up with my iMac.
In the near future I want to expand my Mac with a 1 TB SSD. Looking for one, I found the normal SSD drives with eSATA like the old Samsung I now use with over 500 Mb / sec throughput and the new PRO SSD’s with a PCI 3 interface running at over 3000 Mbyte a second.
I downloaded the free Blackmagic Disk Speed Test app from the App Store and did a quick test. Shocking!!
The internal SSD from my iMac came at almost 2000 Mbyte write and more that 2200 Mbyte read speed.
The external SSD only managed 100 Mbyte write and 330 read.

This means what specs the manufactures give ar the max values you ever can reach. And when you are using an external SSD the speed for writing can be 20 times as slow and reading almost 10 times as slow as my internal SSD.
I hope this also helps.

I did the same tests and I got the same results you got. My external SSD was closer to 500MB/s due to raid 0 and thunderbolt 3 connection. But yes, internal SSDs definitely get much better results. I split my photo library for this reason. I have my active year on my internal SSD.

Thanks for the feedback!