AI Denoise not using dGPU (Metal) in macOS Ventura

Report · Dec 03, 2023

In most recent Lightroom Classic, I'm not able to get the GPU to be used for AI Denoise.

Lightroom is using the GPU for exports and editing, and it is showing the GPU is found (Radeon RX 6800 XT) in the system info and it's using Metal.

But when I try to run AI Denoise, all of my CPU cores run at full throttle and my GPU doesn't spin up. It used to take 3-4 seconds to do an image (24MP Fujifilm RAF), and now it takes over a minute while my CPU is maxed out. I also see that my GPU is only pulling ~30W (basically idle), so I know it's not doing anything here.

Anyone else experiencing this? Seems like a bug.

Lightroom Classic version: 13.0.2 [ 202311290958-8ff975ea ]
License: Creative Cloud
Language setting: en-US
Operating system: Mac OS 13
Version: 13.6.1 [22G313]
Application architecture: x64
Logical processor count: 16
Processor speed: 3.4GHz
SqLite Version: 3.36.0
Built-in memory: 65,536.0 MB
Real memory available to Lightroom: 65,536.0 MB
Real memory used by Lightroom: 11,559.2 MB (17.6%)
Virtual memory used by Lightroom: 62,404.5 MB
Memory cache size: 29.5MB
Internal Camera Raw version: 16.0 [ 1677 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 1102MB / 32767MB (3%)
Camera Raw real memory: 1358MB / 65536MB (2%)
Standard Preview Size: 1440 pixels
Displays: 1) 3840x2160

Graphics Processor Info: 
Metal: AMD Radeon RX 6800 XT
Init State: GPU for Export supported by default
User Preference: Auto

Report · Dec 05, 2023

Operating system: Mac OS 13
Version: 13.6.1 [22G313]

Has Apple not released 13.6.2?

Report · Dec 07, 2023

@GoldingD Apple has release 13.6.2 but only for computers using the M3 chip. The update does not appear for any of my (5) computers. Not sure that has anything to do with the bug.

To add some more clarity on the problem: The GPU was being used with Lightroom Classic 12 for AI Denoise/Enhance Details, as expected. Once I upgraded to Lightroom Classic 13 the GPU is no longer used for AI Denoise/Enhance Details.

This implies that something Adobe changed in Lightroom broke GPU usage for this feature.

Report · Dec 07, 2023

Apparently two different builds, on for old chips that cannot upgrade to Sonoma, the other for M3 chip.

https://appleinsider.com/articles/23/11/07/macos-sonoma-and-macos-ventura-updates-are-here-with-fixe...

No longer a MAC user, so no way to play/test with.

Issues with the GPU on a MAC fixed (if fixed) via MACOS updates.

And yes, Adobe updates, might cause changes in how LrC uses the GPU. and what is required. (but they appear to rarely mention that)