P: Allow users to disable the GPU for AI masking

"Denoise takes a long time, almost 10 minutes. I tried disabling GPU acceleration etc, but Lightroom still uses the integrated GPU."

Adobe inexplicably refuses to have LR's AI commands obey the setting of Preferences > Performance > Use Graphics Processor. The mechanism described here works for some of LR's AI commands:

https://helpx.adobe.com/camera-raw/kb/acr-gpu-faq.html#lens-blur

but it doesn't work for Denoise (I retested just now) and some other of LR's AI commands.

Is this still a problem? I have a desktop computer with a Ryzen 9 9950X 16 core processor and I am using the integrated graphics prosessor of the CPU. So, I have all the CPU power but no GPU power 🙂

This setup is fine for me for everything else except Lightroom. Denoise takes a long time, almost 10 minutes. I tried disabling GPU acceleration etc, but Lightroom still uses the integrated GPU. 

My old laptop denoises images faster with the CPU than my desktop with the iGPU. 

Here is my solution (many thanks to Noell Orridge from Adobe).

Adjust GPU Acceleration: In ACR Preferences, try unchecking Use GPU for image processing

Now it works perfectly. Here are my parameters:

Asus ExpertBook, Intel 255H with 140T iGPU

All drivers up to date (June 2025)

Test data: 45 MPixel, ISO 6400 with a Canon R5

Test performed three times with five images Bridge/Camera Raw AI Denoise from different image series

Battery operation: 100 to 120 seconds/image

Power connection: 72 to 76 seconds/image

Many thanks for this great tip.

is there now perhaps an other option to disable the gpu than DisableGPUInference.txt ?

Unfortunately, LR 13.2 broke the mechanism for disabling use of the GPU by LR's AI commands:

https://community.adobe.com/t5/lightroom-classic-discussions/help-instructions-for-disabling-use-of-gpu-by-ai-commands-don-t-work/m-p/14571912 

Adobe hasn't acknowledged this as a bug or corrected the Help article (it's either a bug or the Help article is wrong).

LR 13 (finally) provides a mechanism for disabling the use of the GPU for AI commands:

https://helpx.adobe.com/camera-raw/kb/acr-gpu-faq.html#lens-blur

Though the help article implies this will disable the use of the GPU for Denoise, Lens Blur, and Masking, my testing indicates it only works for AI masking, not Denoise or Lens Blur (tested on LR 13.0.1 / Mac OS 13.5.1 / Apple M2 Max).

Maybe Adobe wants to exclude those of us who have a 3 year old macbooks thus we have to look elsewhere for editing our photos. Bye 👋

I have a 2020 MacBook Pro 13". I bought the highest spec processor and RAM. There was no option to extend the VRAM. At barely 3 years old it does not meet the minimum spec. I think that is unacceptable.

I have a 2020 MBP fully maxed out on CPU and RAM. I couldnt buy more Vram, it was not an option. So the best I could buy 3 years ago is already not good enough. I suspect the problem can be resolved with some thought. I'm now worried that each update will lazily make my expensive computer redundant.

"a minor but significant frustration"

Unfortunately, it's not so minor for some, in two common instances:]

- LR has decided that an older GPU is compatible with AI masking, but the manufacturer has stopped provided updates to their graphics drivers (e.g. Intel).  So the user can't use AI masking at all.

- LR thinks the GPU is compatible with AI masking but then decides that there isn't enough memory for People masking. So the user can use other AI masking but not People masking.  This is common with three- and four-year-old Macbook Airs that have 1.5 GB of VRAM.

If the user has a desktop computer, they can upgrade the GPU for a couple hundred dollars, but not if they have a laptop.