GPU acceleration uses >90% of graphic card memory - normal?

You nailed it, Todd. Resetting Lr preferences changed everything - now I get 80% - 90% VRAM usage with Lightroom open, just like everybody else. I updated the driver too, but the video RAM graph had already jumped up with the reset.

But then I noticed something extremely interesting. Here's again with PS and Lr busy with several large files. See this dip two thirds in?

That's when I switched from Photoshop to Lightroom. Both applications had been open, but at that point Lightroom became active. Also note how at that point some data are shifted into shared system RAM.

So this appears to work as I suspected from the beginning, and how it really should work: it's a dynamic process, continuously shifting data in and out of RAM as needed. But all the RAM is used all the time.

No performance problems in either Lr or PS.

Dag I see much lower LR GPU memory usage when 'Use GPU for image processing' is unchecked in LR Preferences as shown below. If yours is checked then you may have a corrupted Preferences file. Try resetting it and then recheck 'Use GPU for image processing' in Preferences and make sure you're editing an image with Process Version 5 setting.

I'm using driver version 441.66 and I also have 32GB of system memory. Here's my LR system info:

Lightroom Classic version: 9.1 [ 201911291132-64cf80b4 ]
License: Creative Cloud
Language setting: en
Operating system: Windows 10 - Business Edition
Version: 10.0.18362
Application architecture: x64
System architecture: x64
Logical processor count: 12
Processor speed: 3.6 GHz
Built-in memory: 32715.8 MB
Real memory available to Lightroom: 32715.8 MB
Real memory used by Lightroom: 2981.1 MB (9.1%)
Virtual memory used by Lightroom: 7240.3 MB
GDI objects count: 927
USER objects count: 2933
Process handles count: 1928
Memory cache size: 100.4MB
Internal Camera Raw version: 12.1 [ 351 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 1320MB / 16357MB (8%)
Camera Raw real memory: 1331MB / 32715MB (4%)
System DPI setting: 120 DPI
Desktop composition enabled: Yes
Displays: 1) 2560x1440
Input types: Multitouch: No, Integrated touch: No, Integrated pen: Yes, External touch: No, External pen: Yes, Keyboard: No

Graphics Processor Info:
DirectX: NVIDIA Quadro P2000 (26.21.14.4166)

Application folder: C:\Program Files\Adobe\Adobe Lightroom Classic
Library Path: C:\Lightroom Classic Catalog\Lightroom Classic Catalog-2.lrcat
Settings Folder: C:\Users\Todd\AppData\Roaming\Adobe\Lightroom

Installed Plugins:
1) AdobeStock
2) Any Crop
3) Any Filter
4) ColorChecker Passport
5) Deduplicator
6) DNG Recover Edges
7) Facebook
😎 Fisheye-Hemi
9) Fix Presets
10) Flickr
11) HDR Efex Pro 2
12) jf Data Explorer
13) LensTagger Exif Tool
14) LR/Enfuse
15) LR/Mogrify 2
16) Luminar Flex
17) Nikon Tether Plugin
18) ProShow
19) ProShow Web

Config.lua flags: None

Adapter #1: Vendor : 10de
Device : 1c30
Subsystem : 11b310de
Revision : a1
Video Memory : 5032
Adapter #2: Vendor : 1414
Device : 8c
Subsystem : 0
Revision : 0
Video Memory : 0
AudioDeviceIOBlockSize: 1024
AudioDeviceName: Speakers (Realtek(R) Audio)
AudioDeviceNumberOfChannels: 2
AudioDeviceSampleRate: 48000
Build: 12.1x4
Direct2DEnabled: false

Todd, what driver version are you using?

I'm on 431.70, haven't updated since july last year...old habit. I tend to hang on to drivers that work well.

I still can't get these levels of memory usage with the P2000 5GB. Absolutely no way, no matter what I do, including spot removal.

This is after two hours of intensive work going back and forth between Lightroom and Photoshop, simultaneously working on 20-ish files from from a Sony a7rII at 7952 x 5304 pixels. These aren't small files.

Absolutely flat line. The dip at the end is where I closed Lightroom, while Photoshop is still open.

I'm almost a little concerned that it's not using more memory than it is. Why sit on all this memory if it isn't used?

The 32 GB system RAM is almost fully maxed out during this.

"All my issues went away with new drivers."

Good to hear! I'm not sure why D_Fosse isn't seeing high GPU memory usage since I'm using same Nvidia Quadro P2000 GPU on Windows 10. Regardless of the almost near maximum GPU memory usage both LR and PS simultaneous editing works with no performance issues or crashes. If things go downhill and I start seeing performance issues due to high GPU memory usage then I'll have something to submit to Adobe. Thankfully for now that appears not to be the case for either myself or you. Please let us know if anything changes and I'll do likewise.

I'm nowhere near those levels of VRAM usage in my own testing.

This is a Quadro P2000 with 5GB VRAM. Here's Photoshop open with a number of big files:

And here I launch Lightroom, and start working in the Develop module:

I see the same near maximum GPU memory usage with both LR and PS open, but no performance issues or crashes. Are you still expereincing these issues?

I just ran a test on my Windows 10 system with LR and PS both open sending multiple images to PS using 'Edit in PS.' I applied numerous plugins and did more editing in LR with multiple files open in PS.. My Nvidia Quadro 9000 with 5GB memory stayed at 4.6GB or slightly higher with NO imapct on performance and NO crashes.

Try reintsalling the latest Nviida Studio Driver and not the Game Ready Driver. When installing the new driver make sure to select 'Custom' and check only ‘Graphics Driver,’ ‘Nvidia WMI,’ and 'Clean Install' boxes.

https://www.geforce.com/drivers/results/155648

I'm also using an Nivid Quadro P2000 GPU and have had no VRAM memory usage issues to date.