P: Performance on macOS x86_64 drops when a 2nd screen is connected

[Jollino]

Issue: LR Classic performance on macOS x86_64 drops when a 2nd screen is connected

Lightroom Classic version: 12.0.1 [ 202210260744-9e008017 ]

OS and version: macOS 12.6.1 (21G217)

Machine: iMac (Retina 5K, 27-inch, 2017), 24 GB RAM, Radeon Pro 580 8 GB

Steps to reproduce:

1. Connect a second monitor (in my case a Dell U2212HM)

2. Run LR Classic and edit photos in Develop, note performance especially when adding a few masks; mouse pointer often gets sluggish. Performance marginally improves when disabling other panels, i.e. Detail and Lens Corrections, but remains low and sluggish. The fan often spins up briefly when using brushes. Performance is low even if the second monitor shows no LR Classic windows (in my case just macOS's desktop) 

3. Quit LR Classic, no need to reboot the machine

4. Disconnect the second monitor

5. Reopen LR Classic and keep editing, note performance increases and is on par with what the machine should support, even with all other develop panels enabled. The fan only spins up once in a while on heavier edits.

Expected result: same performance with or without a second monitor

Actual result: just keeping the second monitor connected reduces performance in LR, leading to CPU constantly hitting close to 100% (800% in my case, i7 quad w/ HT). Disconnecting the second monitor restores the expected performance.

Point of note: the internal screen is retina / hi-dpi, the second monitor is not

I understand that these steps are quite empirical and may not be enable to reproduce the issue on other machines. I am able to reproduce it quite consistently on mine, however, and I'm more than happy to provide specific diagnostics, instrument traces or logs that Adobe may require to narrow this down. Note that no other apps seem to exhibit the same issue, not even Photoshop.

LRC's System Info:

———

Lightroom Classic version: 12.0.1 [ 202210260744-9e008017 ]
License: Creative Cloud
Language setting: en-IT
Operating system: Mac OS 12
Version: 12.6.1 [21G217]
Application architecture: x64
Logical processor count: 8
Processor speed: 4.2GHz
SqLite Version: 3.36.0
Built-in memory: 24,576.0 MB
Real memory available to Lightroom: 24,576.0 MB
Real memory used by Lightroom: 2,261.7 MB (9.2%)
Virtual memory used by Lightroom: 39,758.7 MB
Memory cache size: 6.7MB
Internal Camera Raw version: 15.0 [ 1261 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 281MB / 12287MB (2%)
Camera Raw real memory: 359MB / 24576MB (1%)
Standard Preview Size: 2880 pixels
Displays: 1) 5120x2880, 2) 1920x1080

Graphics Processor Info:
Metal: AMD Radeon Pro 580
Init State: GPU for Export supported by default
User Preference: Auto

Application folder: /Applications/Adobe Lightroom Classic
Library Path: /Volumes/Crucial/LR/Lightroom Catalogs/Daniele Nicolucci 2020/Daniele Nicolucci 2020-v12.lrcat
Settings Folder: /Users/jollino/Library/Application Support/Adobe/Lightroom

Installed Plugins:
1) AdobeStock

Config.lua flags: None

———

macOS's System Profiler:

———

Hardware Overview:

  Model Name: iMac

  Model Identifier: iMac18,3

  Processor Name: Quad-Core Intel Core i7

  Processor Speed: 4.2 GHz

  Number of Processors: 1

  Total Number of Cores: 4

  L2 Cache (per Core): 256 KB

  L3 Cache: 8 MB

  Hyper-Threading Technology: Enabled

  Memory: 24 GB

  System Firmware Version: 499.40.2.0.0

  OS Loader Version: 540.120.3~22

  SMC Version (system): 2.41f2

Radeon Pro 580:

  Chipset Model: Radeon Pro 580

  Type: GPU

  Bus: PCIe

  PCIe Lane Width: x16

  VRAM (Total): 8 GB

  Vendor: AMD (0x1002)

  Device ID: 0x67df

  Revision ID: 0x00c0

  ROM Revision: 113-D000AA-931

  VBIOS Version: 113-D0001A1X-025

  EFI Driver Version: 01.00.931

  Metal Family: Supported, Metal GPUFamily macOS 2

  Displays:

iMac:

  Display Type: Built-In Retina LCD

  Resolution: Retina 5K (5120x2880)

  Framebuffer Depth: 30-Bit Colour (ARGB2101010)

  Main Display: Yes

  Mirror: Off

  Online: Yes

  Automatically Adjust Brightness: Yes

  Connection Type: Internal

DELL U2212HM:

  Resolution: 1920x1080 (1080p FHD - Full High Definition)

  UI Looks like: 1920 x 1080 @ 60.00Hz

  Framebuffer Depth: 30-Bit Colour (ARGB2101010)

  Display Serial Number: Y9KCH25L0D0L

  Mirror: Off

  Online: Yes

  Rotation: Supported

  Connection Type: DVI or HDMI

  Adapter Firmware Version: 7.55

———

[Jollino]

Hi all,

I've recently started using Lightroom Classic again after a couple of years of forced hiatus, on the same machine I used before. This is a 2017 iMac with a 5K retina screen, a quad i7 4.2 GHz CPU and 24 GB of RAM, and a Radeon Pro 580 video card with 8 GB of VRAM.

I also recently moved everything to a brand new Crucial X8 SSD, which I measured at 850-900 MB/s read and write.

I have been using an older catalog, which I hve converted to v12 as suggested when I first opened the app (it was earlier converted to v10). I moved both the photo files and the catalog to the new SSD, but I also tried keeping the catalog on the internal SSD (which is even faster, albeit smaller).

The problem is that the Develop module is sluggish, and quite visibly so. It wasn't like this before, and I've used LR since version 7 or so.

Especially when using the Brush for local edits, the mouse pointer itself stutters (!).

I initially thought this may be due to the very heavy 48-megapixel ProRAW photos generated by my iPhone 14 Pro, but even editing the smaller 24-megapixel photos taken with my Sony a6400 isn't much better. The 20-megapixel photos taken with my Canon 7D Mk II are slightly more bearable, but the local edits are still quite nasty.

I've already done all housekeeping, from the most obvious (close other unnecessary apps, make sure smart previews are on, pre-generated 1:1 previews, etc.) to the more esoteric (hide the histogram in the right pane), but the issue persists: at its worst, the fans spin up considerably to try and keep the computer cool... and we're in winter. It also gets worse the longer LR stays open and gets used, so sometimes just quitting and reopening it helps a little bit, but it doesn't last long.

I use iStat Menus Pro and I can see that LR uses up all of the GPU's memory, which is fine, but it's probably not enough for some reason. Disabling GPU acceleration makes absolutely no difference (in fact it actually makes it a little worse).

What I have noticed, however, is that disconnecting my secondary screen makes things faster. Note that I only use LR on the main screen, without anything LR-related on the secondary screen. It does look, however, that just keeping it connected is enough to trigger something in LR that slows everything down to a crawl. I use the second monitor for other, non-photographic work, and fiddling with the cables every time I want to edit photos would quickly turn into a nightmare (just turning it off isn't enough for the Mac to consider it disconnected, apparently).

Has anyone noticed the same issue, or can anyone suggest any solution? Is there any way to provide an official bug report to Adobe for this kind of thing? I'll be more than happy to provide any other information, or do any other test that may be needed.

Attached is the System Info report from LR CC when the secondary screen is connected. When it's not, the only difference is that it only mentions the 5120x2880 internal screen. The used memory values is quite low as I got this just after starting it.

———

Lightroom Classic version: 12.0.1 [ 202210260744-9e008017 ]
License: Creative Cloud
Language setting: en-IT
Operating system: Mac OS 12
Version: 12.6.1 [21G217]
Application architecture: x64
Logical processor count: 8
Processor speed: 4.2GHz
SqLite Version: 3.36.0
Built-in memory: 24,576.0 MB
Real memory available to Lightroom: 24,576.0 MB
Real memory used by Lightroom: 2,261.7 MB (9.2%)
Virtual memory used by Lightroom: 39,758.7 MB
Memory cache size: 6.7MB
Internal Camera Raw version: 15.0 [ 1261 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 281MB / 12287MB (2%)
Camera Raw real memory: 359MB / 24576MB (1%)
Standard Preview Size: 2880 pixels
Displays: 1) 5120x2880, 2) 1920x1080

Graphics Processor Info:
Metal: AMD Radeon Pro 580
Init State: GPU for Export supported by default
User Preference: Auto

Application folder: /Applications/Adobe Lightroom Classic
Library Path: /Volumes/Crucial/LR/Lightroom Catalogs/Daniele Nicolucci 2020/Daniele Nicolucci 2020-v12.lrcat
Settings Folder: /Users/jollino/Library/Application Support/Adobe/Lightroom

Installed Plugins:
1) AdobeStock

Config.lua flags: None

———

For reference, this is what macOS's System Profiler shows about my machine:

———

Hardware Overview:

  Model Name: iMac

  Model Identifier: iMac18,3

  Processor Name: Quad-Core Intel Core i7

  Processor Speed: 4.2 GHz

  Number of Processors: 1

  Total Number of Cores: 4

  L2 Cache (per Core): 256 KB

  L3 Cache: 8 MB

  Hyper-Threading Technology: Enabled

  Memory: 24 GB

  System Firmware Version: 499.40.2.0.0

  OS Loader Version: 540.120.3~22

  SMC Version (system): 2.41f2

Radeon Pro 580:

  Chipset Model: Radeon Pro 580

  Type: GPU

  Bus: PCIe

  PCIe Lane Width: x16

  VRAM (Total): 8 GB

  Vendor: AMD (0x1002)

  Device ID: 0x67df

  Revision ID: 0x00c0

  ROM Revision: 113-D000AA-931

  VBIOS Version: 113-D0001A1X-025

  EFI Driver Version: 01.00.931

  Metal Family: Supported, Metal GPUFamily macOS 2

  Displays:

iMac:

  Display Type: Built-In Retina LCD

  Resolution: Retina 5K (5120x2880)

  Framebuffer Depth: 30-Bit Colour (ARGB2101010)

  Main Display: Yes

  Mirror: Off

  Online: Yes

  Automatically Adjust Brightness: Yes

  Connection Type: Internal

DELL U2212HM:

  Resolution: 1920x1080 (1080p FHD - Full High Definition)

  UI Looks like: 1920 x 1080 @ 60.00Hz

  Framebuffer Depth: 30-Bit Colour (ARGB2101010)

  Display Serial Number: Y9KCH25L0D0L

  Mirror: Off

  Online: Yes

  Rotation: Supported

  Connection Type: DVI or HDMI

  Adapter Firmware Version: 7.55

———

[Jollino]

I forgot to add: the Camera Raw cache is also on the fast SSD, and it's set to 50 GB. Syncing is disabled, as I don't use the LR mobile apps at this time.

[Jollino]

An update: I've been spending more time using LR Classic today after disconnecting the second monitor, and I can confirm that it works much, much better. I'm able to add several masks with multiple layers and it's reasonably smooth, even without disabling any other settings (e.g. Detail or Lens Corrections).

For reference, this is what System Info in LR shows, after editing a few 24 Mpx DNGs:

———

Lightroom Classic version: 12.0.1 [ 202210260744-9e008017 ]
License: Creative Cloud
Language setting: en-IT
Operating system: Mac OS 12
Version: 12.6.1 [21G217]
Application architecture: x64
Logical processor count: 8
Processor speed: 4.2GHz
SqLite Version: 3.36.0
Built-in memory: 24,576.0 MB
Real memory available to Lightroom: 24,576.0 MB
Real memory used by Lightroom: 4,207.0 MB (17.1%)
Virtual memory used by Lightroom: 51,011.6 MB
Memory cache size: 848.9MB
Internal Camera Raw version: 15.0 [ 1261 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 1626MB / 12287MB (13%)
Camera Raw real memory: 1887MB / 24576MB (7%)
Standard Preview Size: 2880 pixels
Displays: 1) 5120x2880

Graphics Processor Info:
Metal: AMD Radeon Pro 580
Init State: GPU for Export supported by default
User Preference: Auto

Application folder: /Applications/Adobe Lightroom Classic
Library Path: /Volumes/Crucial/LR/Lightroom Catalogs/Daniele Nicolucci 2020/Daniele Nicolucci 2020-v12.lrcat
Settings Folder: /Users/jollino/Library/Application Support/Adobe/Lightroom

Installed Plugins:
1) AdobeStock

Config.lua flags: None

———

[Ian Lyons]

> Expected result: same performance with or without a second monitor

With LrC, the secondary screen doesn't make use of GPU acceleration with the result that pretty much everything on the second screen lags the primary screen. Also, since the CPU is now doing the heavy lifting on the secondary screen there's not a lot of resource left for the primary. 

FWIW, I have already submitted a formal bug with near enough the same workflow and expereince as yourself. However, in my case, it's a an M1 Ultra with 64GB or memory 20-core CPU and 48 core GPU. I've also tested using my MacBook Pro M1 Pro with 10 core CPU, 16 GPU 32GB of mamory - same result. 

Edit - I forgot to mention that the M1 Ultra is worse than the M1 Pro, which is worse than my M1 Mac mini. Figure that one out.

[Ian Lyons]

@Rikk Flohr: Photography 

This thread should be merged with https://community.adobe.com/t5/lightroom-classic-bugs/p-performance-on-macos-x86-64-drops-when-a-2nd...

[Jollino]

Hi Ian,

thanks for the update and, before I go further, apologies to the moderators for the other post. I realized that this thread wasn't an "proper" bug report and thought following the expected procedure would be more helpful; I didn't mean to actually complicate things!

I had read about how GPU is only used for the main window, but in my case LrC is running exclusively on the main screen. That's why I thought this may be a bug of some kind: I would expect the second screen to make no difference. I actually spent some time cleaning up my desktop just to be extra safe. Many years ago, probably around OS X 10.4 or so, keeping the desktop littered with files wasn't very healthy, so I tidied up just in case it would make any difference when no other windows (from any apps) were on it. No difference. It's really weird.

While looking around for this, I found this old thread about Mojave. It inlcudes an answer from me, and at the time I had noticed that the second monitor was faster as it wasn't retina. It was a different problem, likely caused by the switch to Metal, but it does make me wonder if mixing retina and non-retina screens may be at the root of this.

Do your external screens happen to be retina / hi-dpi by any chance?

Still, it's somehow reassuring that I'm not the only one with this issue. Hopefully it'll get fixed.

I'm quite surprised by the reverse performance hierarchy you mentioned. What a world!

[Rikk Flohr: Photography]

Adding missing status