GPU crashing in Lightroom Classic -- possible workaround
This has been happening for me through multiple versions of Lightroom, multiple Nvidia graphics cards, and multiple versions (always doing a complete uninstall/install) of the nvidia driver. I have two monitors connected to the graphics card, one for Lightroom and one for email, interacting with my zenfolio account and so forth.
Usually both screens will go black and the system will not respond, requiring a hard reset.
This appears to be a known problem, with many people experiencing it.
My purpose is not to bring up the problem, but to add information I've recently discovered, in the hope it'll help other people.
Turning off graphics acceleration in lightroom preferences does solve the problem, but I work with thousands of photos and the performance hit is too great. I NEED graphics acceleration.
Somewhere along the line in Lightroom development, the "use gpu" was subdivided into "use gpu for display, use gpu for image processing, and use gpu for export". With all of them turned on, I get regular GPU crashes requiring restart.
Why do I know it's a GPU crash? Because sometimes, occasionally, the video will revert to 800x600 on the primary screen. When this happens, the GPU section disappears from the task manager performance tab. Sometimes (less often), the main monitor will freeze but the secondary monitor will still be active. Again, the GPU section disappears from task manager, but I still have some control over the machine. When these things happen, I can usually do an orderly shutdown and I'm back in business. But often, a hard reboot is required to bring the display back.
Having to do the hard reboot to get the display back has the worrying side-effect of occasionally corrupting the library database, necessitating that I recover from a backup. For this reason, I back up the library much more often than recommended.
I keep the performance tab (Windows 10) up while working, and I've noticed that the amount of local GPU memory (6 GB on my card) gets very close to maximum while exporting, and that I'm usually exporting when the blackness occurs.
So, I went into preferences, and turned off "Use GPU for Export", keeping checked "Use GPU for image processing".
Exports now take longer, but since I can continue working while exporting, this isn't a big deal. I've also noticed that CPU usage is much higher, with all six cores stuck at 100% if I have four to six images exporting and working on the next image in the Develop tab.
I noticed at one point that I was reaching the end of my 32 GB of main memory, and since I have swap turned off (for performance reasons) the system has crashed when running out of main memory. Fortunately, ECC memory (I work on an enterprise server class machine) is cheap now days, and I was able to bump up system memory to 64 GB at an affordable price. That particular crash has not happened since.
The interesting thing is that since I turned off use gpu for export, I've done post-processing on about 1500 photos in the last 2-3 days, without a single crash. I used to get 3-4 crashes a day.
So, I'd recommend turning off "use GPU for export", if you're having this problem. It may help.
When I get the money, I want to try a video card with 12 GB local memory, then turn all options on and see if I get a crash. This would tell me if it's GPU memory that's the issue.
Lightroom Classic is a great tool, but it's been a real adventure keeping it running correctly. In fairness, I'm very hard on the software, usually working on 3000 - 5000 photos at a time, and frequently doing mass adjustments. I am definitely a power user, and someone who only works on a few photos at a time probably won't see these issues.
Hope this helps.
