Reduced Frame Rate When Using Dual Screens

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Level 1

18 points

Reduced Frame Rate When Using Dual Screens

After struggling to understand why Motion has been performing so poorly lately, I realized that if I run in Single Display Layout, playback is at full project rate. But if I switch to Timing Pane on Second Display or Canvas on Second Display, the playback frame rate drops from 24 to around 17. This makes it pretty difficult to get animations timed correctly.

Also, I cannot get RAM preview to work properly. It takes forever to render (longer than actually rendering to a file) and as soon as the process is complete, Motion promptly forgets the render. This may be a separate issue that needs a separate thread.

Anyone else notice this kind of problem? I'm running two 4k displays scaled to 3008x1692 and using a 4k 23.98 Motion project.

Thanks,

-Tim

Mac Pro, macOS High Sierra (10.13.4), 6-core 3.5, 64 GB, Dual D700

Posted on Apr 13, 2018 7:28 AM

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Answer 1

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tjreid Author

Level 1

18 points

Apr 16, 2018 7:21 AM in response to BenB

I'm running a Late 2013 MacPro with dual D700 GPUs and I have my monitors each connected to separate Thunderbolt busses. Seems like it should be more than enough to handle it. Especially since all I have in the project so far are 4 shape layers and a ProRes 422 video clip, and Final Cut X typically runs with no issues.

I did discover that if I set scaling on the monitor with the Timing Pane to "default for display" or to "looks like 1920x1080" my frame rate in Motion returns to the project rate.

I guess Motion has difficulty scaling the interface, which is disappointing considering it's a first-party, pro app.

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Answer 2

BenB

Level 6

13,222 points

Apr 18, 2018 4:57 AM in response to tjreid

No, the GPU has to divide between both monitors, T'bolt ports don't matter, it's all in the GPU. All computers do this. On the bright side, you're still getting WAY BETTER performance than AE would give you doing the same thing.

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Answer 3

BenB

Level 6

13,222 points

Apr 15, 2018 6:40 AM in response to tjreid

What Mac model and year are you using?

A second monitor automatically reduces the available GPU resources of an app to half, so yes, this makes perfect sense. You'd need a more powerful GPU.

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Reduced Frame Rate When Using Dual Screens

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