Does the Lightroom 8.4 GPU acceleration address brushing slow downs??

[Bill N99]

Anyone know if the LR 8.4 update includes GPU acceleration for brushing with masks applied?  For versions 8.3 and earlier, its been my experience and apparently the experience of many others (based on searching) that editing slows more and more as more brushing with masks is added during an edit process. 

My system should have plenty of horse power for LR:
I7-4790 processor with 6 cores
32 GB ram
1 TB SSD for executables, catalog,  and cache

4GB 7200 rpm internal drive for images

NVIDIA  GTX 1050 TI with 4GB (LR GPU acceleration is active)

4K display

raw files are between 36 and 45 MB

[dj_paige]

Adobe's announcement is conspicuously missing this detail. Nevertheless, if the GPU (instead of the CPU) is now being used to perform the adjustments (previously the GPU was just used to display the adjustments), an optimist would expect that it should help brushing and spot healing. Or, if you are a pessimist, the lack of any clear statement by Adobe indicates that this doesn't help with brushing.

Why don't you try it?

[dfranzen_camera_raw]

Please try it and let us know if you see an improvement. On a 4K display with a GTX 1050 Ti, I expect that you will see some improvement in this area. I expect that with 8.4 you may see more benefit show up more as you adjust the global or local adjustment sliders after you have added brush strokes, radial or linear gradient corrections than you see during brushing itself. In general, adding more local adjustments adds more compute work for Lr to do as you move the sliders, but using a GPU for some of the work should scale better than using the CPU alone as the number of adjustments increases.

There are a few other caveats to be aware of. First, if your adjustments are not using the latest Process Version (PV5), full GPU acceleration does not kick in. The Auto Mask feature of the brush is still very CPU intensive and a known performance bottleneck; I recommend not using Auto Mask or using alternatives to Auto Mask such as Range Mask. Finally, moire reduction is not yet GPU accelerated 8.4.

I don't know if your PC is a laptop or not, but I know the 1050Ti does come in a few laptop models. The power settings on laptops can have a big influence on performance. Battery saving mode can reduce speed or even change which GPU (if you have both an integrated and discrete GPU) Lightroom gets to use.

[Bill N99]

I had a relatively intensive editing session using LR 8.4.  I did not notice significant improvement in the editing experience.  If I do not use spot healing or brushing with masks more than once or twice, the editing and rendering is reasonable.  However as brushing or healing is added, performance degrades noticeably and in some cases will hang my desktop (see my configuration in my lead-in post above)

A good article by Nasim Mansurov that discusses the same observation is here:
https://photographylife.com/news/lightroom-classic-gpu-acceleration-editing

IMHO, LR suffers from having feature tweeks added over the years, while the core of the program was originally designed for lower resolution images and for 2K style displays.  Features like brushing, radials, gradients using masks are wonderful in concept.  The features invite being used since they work so well in very small doses.   But, with 45MP files that only need toning corrections, would it not be nice to complete the editing process in the raw processor and not end up with needing to use PS and end up with an extra 150-200MB tif to be added to your saved image storage?

[dj_paige]

wnaiman@cox.net  wrote

I had a relatively intensive editing session using LR 8.4.  I did not notice significant improvement in the editing experience.  If I do not use spot healing or brushing with masks more than once or twice, the editing and rendering is reasonable.  However as brushing or healing is added, performance degrades noticeably and in some cases will hang my desktop (see my configuration in my lead-in post above)

Thanks for sharing. This is good to know, even if it is not good in terms of performance.

IMHO, LR suffers from having feature tweeks added over the years, while the core of the program was originally designed for lower resolution images and for 2K style displays.

I don't know how you can say this, are you able to review the code that is in Lightroom and verify that it hasn't changed significantly over the last (let's say) 5 years?

[Bill N99]

Completely true that I have not seen LR code.  That is why I offered my comment as being an opinion, not a fact.  Perhaps I should have used completely different wording.  I apologize if my comment was misleading in any way.

I am a retired IT professional who had responsibilities for a broad range system services in a large organization.  Earlier in my career I was an application software developer and also wrote code for operating systems.