eGPU acceleration with FCPX not working / Catalina

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ImNOT_Human Author

Level 1

12 points

eGPU acceleration with FCPX not working / Catalina

Hello,

I have a Mac Mini 2018 with a Razer Core X hosting a Vega 64 GPU card.

I am under Catalina 10.15.3 and FCPX 10.4.8.

I have selected inside FCPX the external GPU cellbox for rendering and sharing.

GPUs activity monitored using Mac OS apps

Here what I got under FCPX

Rendering: eGPU used
Sharing with Apple Pro Red: eGPU used
Sharing with H264: Iris Pro used only

I have one screen connected on the eGPU enclosure.

I went through many posts and saw eGPU support by FCPX is chaotic and random as soon as MacOS or FCPX is updated.

Any clue?

Mac mini 2018 or later

Posted on Feb 7, 2020 7:09 AM

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Answer 1

Feb 7, 2020 7:59 AM in response to ImNOT_Human

I will try to explain I probably need to write a stickie

GPU is only involved with render and drawer not with compression

Rendering: eGPU used --> as per preferences
Sharing with Apple Pro Red: eGPU used --> it will render again as it can't use the 422 renders and then CPU
Sharing with H264: Iris Pro used only --> reusing the render file brings no or minimal eGPU usage compression goes to CPU using VideoToolBox API that invokes Intel Quick sync

This is normal and is the best possible performance nothing to worry about. eGPU cannot compress it only renders or draw. Once the frames are rendered the CPU compresses them.

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Answer 2

Feb 7, 2020 8:17 AM in response to Interceptor121

To add details for the most technical AMD GPU do not even support CABAC encoding that H264 high profile requires for efficiency so it never compressed with the eGPU even in previous versions

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Answer 3

Feb 7, 2020 5:04 PM in response to ImNOT_Human

Videotool box makes no use of the external GPU in any constellation if your Xeon is on Broadwell it will support quick sync

I do not know which Pro you have but if it has more CPU cores it will beat the mini equally with hardware and software encode

Mojave did not make a difference nothing ever made a difference as an eGPU was never used for hardware acceleration as it is physically not supported. Only Nvidia cards have this capability under windows and linux and they do not work under OSX.

AMD have only Open CL no hardware accelerated encoding or decoding

So compression uses the onboard CPU always did and will continue to do so unless MAC OS starts supporting NVidia cards

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Answer 4

Feb 7, 2020 3:25 PM in response to ImNOT_Human

handbrake does not use GPU uses the same api of final cut pro. I do not know what CPU you have in the mac pro it must be faster
Apple is saying that final cut makes its own choices about which gpu to use and ignore the prefer gpu in Mojave anyway so there is no statement from apple about wonders

As explained to you before Radeon GPU is incapable of doing CABAC compression this has never been possible and never will be only Nvidia have some capabilities but they are not supported under mac os.

It is possible that there are performance regressions in 10.4.7-8 for some users but generally not for the majority and eGPU are a tiny segment of population. I have both 10.4.6 and 10.4.8 installed and I can confirm sharing works identically on my vega64

A bug is when something does not work as expected and here things work as expected so this is going nowhere

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Answer 5

ImNOT_Human Author

Level 1

12 points

Feb 7, 2020 4:41 PM in response to Interceptor121

Hi,

Are you reading my posts ?

1) In my Mac Pro, I have an AMD RX 580 and it is OBVIOUS to check if CPU only (H264 encoding) or CPU+GPU (videotool box H264 encoding) is used with activity monitor! I repeat again: with videotool H264 the encoding is 50% faster with the AMD RX580 plugged into the Mac Pro versus the Iris GPU in the Mac Mini, with the same video!

Still with the Mac Pro, by selecting only H264 encoder using exclusively the CPU, I get roughly same encoding time than the Mini with same option, which is consistent with Geekbench scores for my two configurations.

2) Why are you speaking about Mojave? Did you read the title: my configuration is Catalina 10.15.3 and I am speaking about the cellbox you can find in Preference Menu inside the apps

I appreciate any contribution but if you are bringing arguments telling me it works with Mojave, that’s great for you. But it is not my question.

I call a bug when the program is using randomly the embedded GPU or a combinaison of both, with same video leading to get +250% encoding time more.

Do you reasonably think I have time to waste to report fakes here? I am here to share my issue and to try to check what is wrong in my set up and try to find a workaround without the need to downgrade my configuration.

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Answer 6

ImNOT_Human Author

Level 1

12 points

Feb 7, 2020 3:16 PM in response to Interceptor121

Sorry guys but you are all wrong. It appears I have an old Mac Pro on which I have stuck an AMD 580.

Then I could compare using Handbrake and selecting same video with Videotool encoding checked RX580 versus Mac Mini running as well Handbrake: what does take around 55s with the Mini takes less than 30s with the RX580. As my Mac Pro has Xeons, Quick Sync is not available.

And this is also what the guys having an Imac Pro can find.

When I decide to select the external GPU for sharing, I must not detect Apple is overdriving my decision!! If Quick Sync is SO GOOD, then I would be smart enough to keep it! This is as simple as this: we must get what the option selection is supposed to provide.

But what does upset me, I do not know how but 1 day before I was rendering the same scene and by monitoring the two GPUs, they were equally used and the encoding time was 2mn09. Yes, I got the figure cause I did many times to confirm.

And yesterday without having changed any set up, the Iris Pro is 100% loaded and sharing time is now almost 6mns!!!

Values do speak and for me there is a HUGE bug.

Only thing I know, claiming eGPU is wonderfully supported by Apple Apps is just a joke.

And I repeat again: just type FCPX / eGPU / not supported and you will get tons of stories similar complaining a massive decrease in performances after making either macOS or FCPX changed. And all are using AMD’s GPU in their enclosures as well.

So reading above, Quick Sync does it better just let me laugh and wondering if some are just reporting marketing propaganda from Cupertino!!

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Answer 7

Feb 7, 2020 7:19 AM in response to ImNOT_Human

Sharing to H264 is mostly handled by the CPU, which has hardware acceleration for this (Intel QuickSync - not sure if this is the correct spelling) or by the T2 chip in machines that have it.

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eGPU acceleration with FCPX not working / Catalina

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