Dual Graphics Card - Flickering Issue

[Johnnieob]

I've recently  purchased a new laptop with both an Intel Graphics UHD 630 and Nvidia GTX 1660 Ti which is causing me some issues. When adjusting any slider in Lightroom or Photoshop the canvas & areas around it flickers. I've searched high and low for a fix, even contacted Nvidia and Adobe which was not helpful. I have also used Nvidias control panel to make sure that only the 1660ti is powering the applications. A weird temp fix is going into device manager, disabling the onboard graphics; yet i dont want to do this everytime i need to edit a photo. It appears Adobe has troubles with dual graphics cards, does anyone know a fix for this?

[Ian Lyons]

Photoshop and Lightroom tend not to use the integrated Graphics when a descrete card is present. That being said, it is the OS or the graphics control software that switches from one to the the other not Photoshop or Lightroom. Based on your description of how to reduce prevent the flicker I supsect that the more likley cause of your issue is that the control software is making the required switch from integrated to descrete. Have you checked whether new drivers are available from nVidia?

BTW, Dual graphics cards (i.e. integrated and descrete) have been working fine since their inception with both Photoshop and Lightroom.

[D Fosse]

It doesn't work well at all in Photoshop, where it's a recurring issue in the forum.

https://helpx.adobe.com/photoshop/kb/photoshop-cc-gpu-card-faq.html 

"Multiple graphics cards with conflicting drivers can cause problems with graphics processor accelerated features in Photoshop (...) If you have to use more than one graphics card, make sure that they are the same make and model. Otherwise, crashes and other problems can occur in Photoshop."

[Conrad C]

A point of clarification might be in order. I'm not sure this problem would fall under the issues Photoshop has with multiple graphics cards. I've been under the impression that the warning about Photoshop and multiple graphics cards is about multiple discrete graphics cards, as in a desktop computer. But this isn't really a case of multiple graphics cards; this is about discrete graphics and integrated graphics. That is a slightly different case that should normally not cause a problem; I agree with Ian here that it's probably an issue with the OS or graphics driver.

I know that this is a Windows thread, but for example, one of the most popular laptops in the Adobe user base is the 15" (now 16") Apple MacBook Pro. That laptop has shipped for over a decade with both discrete graphics and Intel integrated graphics, and automatic switching between them controlled by the OS, and Lightroom and Photoshop have had absolutely no problem with it in all those years. That's a big reason I think the issues with this Windows laptop may not be with the applications, but more likely by the graphics hardware handling at the OS or driver level.

[D Fosse]

OK, that may be. I've only ever had a single GPU so I wouldn't know.

Still, it's hard to imagine how this (integrated/discrete GPU) can possibly work seamlessly. What if you have calibrated the screen and there are calibration tables to be loaded? Which GPU does it go to? What about display color management, where the profile conversions are executed in the GPU using OpenGL/Metal? And not the least - what about OpenCL functions, like e.g. Select and Mask, Field Blur, Iris Blur, Smart Sharpen etc etc? Here the math is done in the GPU, and the result then fed back to Photoshop. What happens when the GPU switches mid-calculation? Crash?

I just can't get this to make sense. Data pass back and forth between Photoshop and the GPU all the time, it's not a one-way street.

Right. This is the Lightroom forum, sorry 😉 AFAIK Lightroom's GPU use isn't quite as extensive.

[Conrad C]

I don't know the answers to some of those questions. But I can guess at some of them. For example, if you use a GPU-accelerated function, I think Photoshop simply sends it to the graphics hardware that's currently active. In the MacBook Pro example I mentioned, I don't think both graphics options are active at the same time: The Photoshop feature uses the active graphics, and not the other. Probably because macOS blocks access to the graphics that are not active.

That may be where part of the difference is; in a Mac or Windows system with two discrete graphics cards it may be configured for both to be active. That is the case that isn't reliable because Photoshop doesn't support it.For the Windows laptop in question that has both Nvidia discrete and Intel integrated graphics, now the question is how that laptop is designed to use the two graphics options. If it treats them exclusively — only one active at a time, like a MacBook Pro — there should be no problem. But if it handles them like two discrete graphics cards active simultaneously, then that's what Photoshop wouldn't support.

Your question about display color management is a good one. On my Macs with dual graphics (or an eGPU), for some reason I don't think about whether the calibration/profiling results might be different depending on which graphics system is active. But then again, it's not something that's always mentioned in the instructions for calibrating or profiling devices.

[GoldingD]

The vast majority of the world wide Adobe customer base has computers be they laptop/notebook or desktops with both Descrete GPUs and integrated video controll. Only a few have just integrated (old laptops, ancient desktops). And extremely few have any issues with that. Normally Photoshop, Lightroom, and Lightroom Classic ignore the integrated video controll.

For both laptops/notebooks and desktops the integrated video control is on the motherboard.  Laptop/notebooks have the GPU on the motherboard as well, desktops on an add on card. All in ones like IMacs a bit different.

Normaly you do not have to accomplish any tweaking.

As for Dual Graphics cards, that issue is all about Descerte Graphics cards. This is usually something hard core gamers have, but normally they have two absolutly identical cards connected together. Problems would occur if the two cards had different drivers (as such probably different cards)

Will try to follow with some Adobe links

[GoldingD]

Please post your system information as Lightroom reports it. In Lightroom click on Help. then Systeem Info, then Copy, post in a reply. 

[GoldingD]

From your remarks I imagine you have looked at the following, but in case...

https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html

You might want to temporarily as a diagnostic accomplish step 6 in solution 4, for that matter, work thru solution 4. Note that this does not have to be temporary, does not have to be undone when you exit Photoshop/Lightroom, as long as it does not foul something else up.

no gaurentees

Ahh, by going to my PC and looking at my Device Drivers, I was reminded that some of us disable the integrated video within our Bios settings.