Photoshop Fails if More Than One GPU in System

Forum|Forum|2 years ago
July 26, 2023
6 replies
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I've worked through support on this issue and it is not resolved. I use a Mac Pro 2019 with two Radeon Pro W6800X MPX units (four GPUs) and one Radeon RX 6800 XT. If 'Use GPU' is checked in Settings->Performance I cannot open any file. If I un-check 'Use GPU' I can open files but some features are not available (e.g., Generative Fill, Normal Map creation) and Photoshop will not shutdown properly. I have to fource quit it. Support says, simply, Photoshop does not support multiple GPUs on MacOS.

Reporting this here in case anyone knows a workaround and in the hope we can get others with this issue to put some pressure on the devs to prioritize this bug.

Please respond if you know a workaround or have the same issue.

Thanks,

Greg

macOS

This topic has been closed for replies.

G

Gregory27652298gmcmAuthor

Participating Frequently

@D Fosse

Interesting. I *think* that the Cinema 4D's Pyro feature and Insydium's Nexus also use the GPU for data processing not only for graphics. Also, when rendering, e.g., with Redshift which happily uses all five GPUs and the CPU sends data to the GPU and gets back data which is then displayed. So these apps are not using the GPU to drive the display but to compute on data. Seems that Ps could do the same, no?

Greg

D Fosse

Community Expert

The problem is that this isn't a simple one-way downstream flow, like it used to be and still is in simpler applications.

Photoshop uses the GPU for actual data processing, and the result returned to Photoshop for further processing. You can't send data to one GPU and get it back from another. There can only be one GPU in this equation.

There is no way several GPUs can be active at the same time. But there should be a way to easily "lock" Photoshop to one GPU, so that it's not necessary to disable the other. The fact that this is still not possible, suggests that it's an OS limitation, not a Photoshop limitation. This has been reported so many times, in so many years, that the problem is very well known.