Mac lagging while LR exports or renders previews

[Cornelius]

Hi guys

Maybe anyone has an idea or seen the same issue.
Whenever Lightroom is rendering previews (1:1 previews) or exports JPEGs the whole Mac OS system is lagging. Writing emails is nearly impossible, as the entering text is lagging, surfing in the web is lagging etc etc.

Current hardware: MacPro 2019, 12-core Xeon, 96GB RAM, 5700x GPU and a lot of SSD storage.
Software: Catalina (latest version) as also latest Lr version

I have seen the same effect also on my old MacPro 2013 with 6-core Xeon, 64GB RAM and D700 GPU but never on my MacBookPro 13' with just a standard i7 quad core.
When I look at the cpu usage stats (istats menu) and compare the MacBookPro and what I see on the MacPro's. On the MacBookPro the CPU usages during 1:1 preview or export rendering is about 75% on all cores/hyper threading cores. On the MacPro the CPU load is constantly at 100% on all cores/hyper threading cores during the same tasks. For me it seems, that on XEON CPU's Lightroom just grabs all system resources and blocks them, so that even writing mails gets impossible. On the i7 CPUs the load seems to be reduced, so that that other software and the OS has enough resources left to run smoothly.

Are there other users with Xeon CPUs (MacPro or iMac Pro) out here in the forum, having the same performance/lagging issue on their machines while rendering previews or exports in Lr?

[George Marinos]

Hi Cornelius.
I had exactly the same problem until some updates ago. Now the problem is gone and you can see my system's  information in the attachments.

[George Marinos]

Also

[Cornelius]

Hi George - thx for your feedback. It's really strange. I've seen the issue under Mojave and now also with Catalina. 🥴
Well, I might try to reinstall the whole Mac after my summer vaccation from scratch without using TimeMachine.

[Chris Kern]

Whenever Lightroom is rendering previews (1:1 previews) or exports JPEGs the whole Mac OS system is lagging. Writing emails is nearly impossible, as the entering text is lagging, surfing in the web is lagging etc etc.

It's difficult to diagnose a problem like this without instrumenting the system that is experiencing them, but what you're describing sounds to me like an operating system bug: i.e., Apple's problem, not Adobe's.  If I had to hazard a guess, perhaps some error in the way Apple has implemented the application programming interface for using the graphics subsystem as an auxiliary processor.  While UNIX provides excellent separation between supervisor (i.e., operating system) and user (i.e., application) processes, there is a glue layer that connects specific hardware subsystems to the more generalized operating system, and my guess is that Apple may not have implemented it properly for higher-performance graphics devices.  (It's interesting, I think, that I have never experienced the symptoms you describe on my 2013 Mac Pro, which also has a six-core Xeon module but D500 GPUs.)

One possible test of this conjecture would be to select the Performance tab in the Lightroom Preferences panel and set the "Use Graphics Processor" option to off, as well as to disable the "Generate Previews in parallel" checkbox.  Then render some previews or export some JPEGs and see if the symptoms persist.

[Cornelius]

@ Chris
Thx for your feedback. Gonna try the different settings in the Performance tap after our vacation.

Interestingly I did not have the issue on my 2013 MacPro over the whole last 7 years. The lagging started somewhere spring/summer 2019. My hope actually was, to get rid of the issue by upgrading to a 2019 MacPro. Unfortunately it's still there.

Do you think my two 4k Monitors (one EIZO CG318 and one Dell UltraSharp 24' 4k) could be causing a problem here? I know that Lr still doesn't like 4k monitors..

[Chris Kern]

Do you think my two 4k Monitors (one EIZO CG318 and one Dell UltraSharp 24' 4k) could be causing a problem here? I know that Lr still doesn't like 4k monitors.

I don't have any experience with 4K monitors, but I'm more inclined to think the symptoms you are experiencing are related to the way MacOS is using the graphics card for rendering your previews and your exported JPEGs rather than some problem with the device drivers for your monitors.

[Cornelius]

Hi Chris

Thx
Would you think, reinstalling the Mac without using a TimeMachine backup could help. All my data is anyway stored on external drives and on Synology Dive/Dropbox. So a reinstallation from scratch would not be a big thing..

[Chris Kern]

Would you think, reinstalling the Mac without using a TimeMachine backup could help. All my data is anyway stored on external drives and on Synology Dive/Dropbox. So a reinstallation from scratch would not be a big thing..

There is no plausible reason to reinstall the operating system.

If you want to disable TimeMachine, just turn it off by unchecking the "Back Up Automatically" box in the TimeMachine preferences (see attachment).

[Cornelius]

@ Chris
I just thought, if there is something "wrong" with the OS, as I have read a post in Adobes support forum from another user with a similar issue. There it helped to install the OS incl. all software from scratch without using a TimeMachine backup. As I have never installed my Macs "fresh" sind over 10 years, there are quite a lot old files within the system folders which are definitely not used anymore.

Well, I gonna try exporting without GPU acceleration after my vaccation and also try to uninstall and reinstall the Adobe suite using the Adobe Cleaner tool. Also here, I have some much old Adobe files on the Mac, that this might be a good thing to do anyway.

[digitaldog]

Just saw this on an Adobe site, not sure if it's pertinent or not but FYI:

If you're a nvidia gsync user and experiencing mouse stuttering in Ps (and all Adobe apps), try turning off gsync to see if that resolves the issue.
Basically what happens is that any activity in an Adobe app will result in 2-3 seconds of micro-cursor stuttering (looks like frame rate dropping) and the occasional 3-4 seconds of cursor freeze. Disabling gsync fixes the issue. This behavior appears only in Adobe apps and none other.

[Chris Kern]

Would you think, reinstalling the Mac without using a TimeMachine backup could help. All my data is anyway stored on external drives and on Synology Dive/Dropbox. So a reinstallation from scratch would not be a big thing..

I just thought, if there is something "wrong" with the OS, as I have read a post in Adobes support forum from another user with a similar issue. There it helped to install the OS incl. all software from scratch without using a TimeMachine backup.

OK, now I understand your previous question.

Your 2019 Mac Pro would have had the then-current version of the operating system pre-installed when you acquired it.  When you restored your files from the TimeMachine back-up, Apple's Migration Assistant should not have attempted to replace the operating system that came pre-installed on the new computer with the copy of the operating system from your old computer that was stored on the back-up.  (I don't know how this would have been possible, even if you deleted the pre-installed operating system from the new computer before trying to perform the restore, since unless the two machines were identical they would have had different hardware architectures and subsystems, and therefore required different modules of the software that "glues" the hardware to the more general, higher-level parts of the operating system.)  So when you started using your new Mac Pro with the files collected from the back-up, presumably you were using a fresh installation of the operating system.

If your problem is caused by a bug in the operating system or (more likely) in a device driver―i.e., something that Apple needs to fix by releasing a patch―reinstalling the same operating system bundle would also reinstall the bug.

[George Marinos]

Just saw this on an Adobe site, not sure if it's pertinent or not but FYI:

What is gsync?

[Cornelius]

Back from vaccation

Today I could test what happens, when I switch of the GPU acceleration. Nothing..
Without GPU acceleration the Mac still lags during exporting and 1:1 preview rendering. Writing emails is impossible as typing lags and often letters get lost..

Pretty annoying this issue..

[Chris Kern]

Without GPU acceleration the Mac still lags during exporting and 1:1 preview rendering. Writing emails is impossible as typing lags and often letters get lost..

OK, with Lightroom-specific use of the graphics processor ruled out, the next thing I would suspect would be the transitory and mass storage devices.  Assuming you're saving your catalogs/previews and exported images on an internal (solid-state) drive, either that drive could be thrashing or you could have a problem with a module of your primary memory.  A failure of either type of component could conceivably produce the symptoms you're experiencing.  The Apple Diagnostics test isn't perfect, but I've used it successfully to identify hardware problems in the past.  If you haven't already tried it, that's what I would do next.  If the test identifies a problem, it provides a diagnostic code to indicate which hardware component may not be working properly.

[Cornelius]

Hi Chris - we can exclude mass storage devices, as the issue persists since a couple of month on two different MacPro (2013 & 2019 MP) and is independent from importing/exporting on internal, external Thunderbolt RAID or NAS storage or internal PCIe NVMe SSD storage. 🤷‍♂️

I also tried different Lr catalogs on both machines. Did not help.

My next guess really would be a clean installation from Adobe software using the Adobe Cleaner tool to remove every Adobe file from the system.
Any other ideas?

[Chris Kern]

Any other ideas?

Just to try running the Apple hardware diagnostics, and see if they identify a component problem.  It's difficult for me to come up with a plausible theory why a Lightroom configuration problem would cause the kind of i/o delays you are experiencing when you use other software, but I have no knowledge of Lightroom's internals.  Since you installed Lightroom on the new machine from a back-up of the old machine's filesystem, perhaps a fresh install of the Adobe software is worth trying.

[Cornelius]

@Chris

Gonna try the fresh install until end of this week. Tomorrow I have a big photo production and will not be at the office at all.
I did perform a hardware test of the old MacPro 2013 middle of June prior I sold it. Diagnostic said, all good.

Lets see if the clean reinstallation of Adobe software helps.

[kimballistic]

You're going to get much better recommendations on Adobe's own forums:

https://community.adobe.com/t5/lightroom-classic/bd-p/lightroom-classic

https://feedback.photoshop.com/photoshop_family/categories/photoshop_family_photoshop_lightroom

Including possible responses from Adobe's own engineers.

Personally, my guess is you've got "Generate Previews in parallel" enabled, and that's greedily using every core to the max.  Same with exporting, although I don't think there's a preference for whether that one runs in parallel or not.

[Cornelius]

Hi kimballistic

You're right, "Generate Previews in parallel" was enabled. Just disabled the function AND now it works better. Still, writing text in Apple Mail or in Safari lags quite a bit, but much less. So at least, it is now possible to write some simple text lines. Before it was impossible.

But still, compared to my little MacBook Pro 13', the MacPro 2019 and my experience on my former MacPro 2013 is much worse. On the MacBook I really can work normally while Lr renders previews or exports. Safari, Mail, Netflix , InDesign, Word, Excel just work without any lags. On the MacPro I still have quite some lags even though the MacPro is a much more powerful computer. 🤷‍♂️

I gonna look into the Adobe Lr forum and see what hints I can get from there. 👍🏻

You're going to get much better recommendations on Adobe's own forums:

https://community.adobe.com/t5/lightroom-classic/bd-p/lightroom-classic

https://feedback.photoshop.com/photoshop_family/categories/photoshop_family_photoshop_lightroom

Including possible responses from Adobe's own engineers.

Personally, my guess is you've got "Generate Previews in parallel" enabled, and that's greedily using every core to the max.  Same with exporting, although I don't think there's a preference for whether that one runs in parallel or not.