Lightroom Classic: Incredibly slow on iMac Pro

I was a Mac IT pro for 25 years. Sometimes it’s the MacOS that’s the problem.

To rule out a corrupt cache or application state, or directory damage, please give your Mac the "once over"! Run the free Onyx (titanium-software.com), select the Onyx version for your OS, download, run it, reboot. (In Onyx run almost everything in the Maintenance tab, deselecting things you may not want deleted, like Launch Services . Hit the "Options" button and deselect more stuff like Cookies & Other Site Data, Browser History, Form Values, etc.(if you don’t know what something is, look it up, or don’t run it, or ask me), then hit Run Tasks. After it's done it will ask for a reboot.

If that doesn’t fix it run Disk Warrior if you can ($120), (https://www.alsoft.com) from an external boot drive, reboot. If you can’t do Disk Warrior, at least run First Aid from Disk Utility (boot into Recovery Mode, Command-R, to run Disk First Aid). Also just doing a "Safe Boot" can clear out caches (restart, hold down shift until you see "Safe Boot" on the screen, let it fully boot, then reboot normally.

If that doesn’t work try launching Lightroom from your other (admin or test) account, with a new catalog, as a test. Does it run OK? If it does it may be a corrupted preference in your Username/Library folder. To reset your LR preferences:

1. Close Lightroom.
2. Hold down [Alt/Opt]+[Shift] while restarting Lightroom.
3. Overwrite the Preferences when prompted by the dialog.
4. Close Lightroom.
5. Restart Lightroom.

Let me know if it worked?

Hi Carlos, thanks you very much for your post. I tried everything, but still can't work with big photos. When I use local tools it starts freezing. It works pretty normal with normal photos(it should fly) but when I try to edit a panorama, it stucks. It is even slower than my old 2011 iMac or MBPro. It was like this since I first installed OSX and LR. When I start Lr it seems to work fine until 5 min  It works well with Photoshop and many others imaging soft . Lr is the only one with problems. Same files with Capture One, fly!  
I've been 4 month trying to solve. I was told that the architecture of Lr was not designed to work with more than 4 cores, they should redesign it completely and it looks is not something they will do. I know Lr works fine for the general user which are amateur photographers. But  I really need to work seriously  with big files. The best solution I found is to migrate to Capture One which by the way produce much better quality images(way better sharpening and dynamic range). It is not something nice to do because I have more than 300 thousands images in Lr  to migrate and learn how to use the soft, but  I have no option.. 
Thank you any way

Eliseo don’t believe most of what you read on the internet! I have 8 cores, and I see with Menu Meters all 16 threads at 100%, so the “4 core myth” is just that, a myth. It’s surprising to me that many on this thread assume it’s Adobe’s fault and don’t even bother to CALL TECH SUPPORT? Eliseo, I bet there’s a local Mac tech that you could hire (there’s no substitute for being onsite) that might see something I can’t (from Chicago). Try it!

PS-what happened when you used another account, and created a new catalog, and imported some big images? Did it run OK? Did you reset your preferences? Deleting (start with the Adobe way, finish with App Cleaner) and reinstalling LR would be my next approach if you really tried everything I suggested?

Please post your Lightroom>Help>System Info...

If your on macOS 10.14.6, Apple posted a supplemental update (build number 18G95) a couple of weeks ago that fixes some performance issue that seriously impact a number of applications such as Lightroom. Please keep your macOS up-to-date. 

I contacted apple because all of a sudden I have been having so much trouble using Photoshop and forget about Lightroom, its not worth it. My computer is 32 bit and they have gone to 64 bit!!! :( So he told me my computer is no longer able to support it well.

Actually that’s completely incorrect, your iMac Pro is 64-bit, as all Macs have been for YEARS! If Adobe didn’t update its software to 64-bit it would stop working when you upgraded to the next version of the Mac OS (Mojave is the LAST version that will support 32-bit apps!) Get a REAL Mac Tech to help you, you know, as in “call the Help Desk”?

Hi Carlos. I already installed Lightroom three times, one time was a person of Adobe Help center who took control of my Mac and did several things as reinstall Lr. but nothing changed.

Hi Simon Chen,

I'm running on OS Hi Sierra 10.13.6 and did all the updates. 
Here is the system info:
Thank you,

Versión de Lightroom Classic: 8.4 [ 201908011719-03751b60 ]Licencia: Creative Cloud
Configuración de idioma: es-AR
Sistema operativo: Mac OS 10
Versión: 10.13.6 [17G65]
Arquitectura de la aplicación: x64
Cantidad de procesadores lógicos: 16
Velocidad del procesador: 3,2 GHz
Memoria incorporada: 32.768,0 MB
Memoria real disponible para Lightroom: 32.768,0 MB
Memoria real usada por Lightroom: 13.267,9 MB (40,4%)
Memoria virtual usada por Lightroom: 26.406,8 MB
Tamaño de memoria de caché: 2.112,2MB
Versión interna de Camera Raw: 11.4 [ 273 ]
Número máximo de subprocesos que usa Camera Raw: 5
Optimización de SIMD de Raw de cámara: SSE2,AVX,AVX2
Memoria virtual de Camera Raw: 6257MB / 16383MB (38%)
Memoria real de Camera Raw: 6306MB / 32768MB (19%)
Pantallas: 1) 5120x2880

Información de procesador gráfico: 
Metal: AMD Radeon Pro Vega 56



Carpeta de la aplicación: /Applications/Adobe Lightroom Classic
Ruta de la biblioteca: /Users/seo/Pictures/prueba/prueba.lrcat
Carpeta de ajustes: /Users/seo/Library/Application Support/Adobe/Lightroom

Plugins instalados: 
1)  Plug-in de conexión al equipo de Nikon
2) Adobe Stock
3) Facebook
4) Flickr
5) HDR Efex Pro 2
6) Helicon Focus Export
7) Impresión de Mirage
8) Plugin importador de Aperture/iPhoto

Indicadores config.lua: None

AudioDeviceIOBlockSize: 512
AudioDeviceName: iMac Pro Speakers
AudioDeviceNumberOfChannels: 2
AudioDeviceSampleRate: 48000
Build: 12.1x4
CoreImage: true
GL_ACCUM_ALPHA_BITS: 0
GL_ACCUM_BLUE_BITS: 0
GL_ACCUM_GREEN_BITS: 0
GL_ACCUM_RED_BITS: 0
GL_ALPHA_BITS: 8
GL_BLUE_BITS: 8
GL_DEPTH_BITS: 24
GL_GREEN_BITS: 8
GL_MAX_3D_TEXTURE_SIZE: 16384
GL_MAX_TEXTURE_SIZE: 16384
GL_MAX_TEXTURE_UNITS: 8
GL_MAX_VIEWPORT_DIMS: 16384,16384
GL_RED_BITS: 8
GL_RENDERER: AMD Radeon Pro Vega 56 OpenGL Engine
GL_SHADING_LANGUAGE_VERSION: 1.20
GL_STENCIL_BITS: 8
GL_VENDOR: ATI Technologies Inc.
GL_VERSION: 2.1 ATI-1.68.20
OGLEnabled: true
GL_EXTENSIONS: GL_ARB_color_buffer_float GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_non_power_of_two GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_transpose_matrix GL_ARB_vertex_array_bgra GL_ARB_vertex_blend GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_clip_volume_hint GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_depth_bounds_test GL_EXT_draw_buffers2 GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_two_side GL_EXT_stencil_wrap GL_EXT_texture_array GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc GL_EXT_texture_env_add GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_rectangle GL_EXT_texture_shared_exponent GL_EXT_texture_sRGB GL_EXT_texture_sRGB_decode GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array_bgra GL_APPLE_aux_depth_stencil GL_APPLE_client_storage GL_APPLE_element_array GL_APPLE_fence GL_APPLE_float_pixels GL_APPLE_flush_buffer_range GL_APPLE_flush_render GL_APPLE_object_purgeable GL_APPLE_packed_pixels GL_APPLE_pixel_buffer GL_APPLE_rgb_422 GL_APPLE_row_bytes GL_APPLE_specular_vector GL_APPLE_texture_range GL_APPLE_transform_hint GL_APPLE_vertex_array_object GL_APPLE_vertex_array_range GL_APPLE_vertex_point_size GL_APPLE_vertex_program_evaluators GL_APPLE_ycbcr_422 GL_ATI_blend_equation_separate GL_ATI_blend_weighted_minmax GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_IBM_rasterpos_clip GL_NV_blend_square GL_NV_conditional_render GL_NV_depth_clamp GL_NV_fog_distance GL_NV_light_max_exponent GL_NV_texgen_reflection GL_NV_texture_barrier GL_SGI_color_matrix GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod 

Your system looks to be a fairly performant system. The key is that you are driving a 5K monitor. Try the following:

1. Checkout https://helpx.adobe.com/lightroom-classic/kb/lightroom-gpu-faq.html and make sure you upgrade your macOS to minimum macOS 10.14 or later (macOS 10.14.5 or later is recommended) so that you can take advantage of the best GPU acceleration. 

2. Make sure that you enable Lightroom GPU acceleration for both display and image processing.

3. At last, troubleshooting by turning off the few 3rd party Lightroom plug-ins (Lightroom>File>Plug-in Manager... to see if it makes any difference.

Hi Simon, 
Thanks for your help. 
I did the upgrade to the latest Mojave, I checked the GPU and it is enabled . I Turned off all the plugs in ... but it is still the same, it became very very slowly when I start using local tools. 

I have tried everything suggested in the Adobe Help center, and severals forums.  I thought It could be a failure on the iMac  but I can work perfectly with all the others software, even photoshop works well.
There is a lot of people who have problems with iMac and Lr ... any other Idea ?   I just cannot work like this. It takes about 25 second to generate the 1:1 preview , is it normal? Worked much faster with my old iMac 2011.

I tried creating another account in the iMac, and making a new catalog, reinstall it, ... 
The only thing that has changed a little bit  (only a little bit) it was when I opened Lr in low resolution mode.


I've been using Lr since the first Beta, and never have this issue. 

Thank you

Could you show a screen cap of your "About This Mac" dialog?

Do you experience the same slowness if you try create a brand new catalog and has the image file reside on the internal disk?

Try post a copy of the photo & related xmp settings online that demonstrate the slowness, and we'll try to reproduce it if we can.

Hi Simon, sorry my delay...
I made a brand new catalog with the images in the internal disk and made another user. At first it worked better, but after using it for a while working with brush and radial filters  it started freezing for moments (color wheel). When I go to fullscreen it takes between 10 and 20 second to generate a full preview. 
Normally I have all my images (300 000) in a Drobo which is Thunderbolt 2. I tested the writ and read speed and it is quite good. 
Here are some links to some images from my catalog and the screen shot of About my Mac.

Thank you!

Eliseo

https://adobe.ly/2nuGNfm

https://adobe.ly/2lXxHaw
https://adobe.ly/2mWF7uE

https://adobe.ly/2lOSa1l

What version of Drobo? The versions from before like 5 years ago were very unreliable, their "Beyond RAID" software wasn't up to professional standards in actual practice, and totally failed in some restores. Try putting a subset of images, like one folder, on a regular external hard drive (or your internal drive), import them into a NEW catalog, and see if that improves it. If it does, then it's the Drobo.

Same issues here with Mb pro 2016

@eliseo what you haven’t checked is hardware issues. Bad RAM happens all the time, your drive(s) could be failing etc. I would take it back to an Apple store (after a full clone with Carbon Copy Cloner), and ask them to check all hardware or give you a replacement.

I’ve seen this to be the problem before.

Now that you are at MAC OS  Mojave, create a new screenshot of your About this MAC again. Want to see the build number.