Aux Sends causing high CPU usage PT 2021.6/higher with Apple Silicon [FIXED 2022.5]

[audiogamble]

I communicated on the forum yesterday that I've had significant performance issues with Pro Tools on my Apple Silicon computer since it's first officially supported release, Pro Tools 2021.6 . I believe I've finally tracked down the root of the problem - Aux Sends.

I've set up a test session to isolate the problem, located here. Please feel free to download it and post your results, including information on your Pro Tools version and computer specs: https://www.dropbox.com/sh/1c16zw2jp...yyw862tOa?dl=0


How the test works:

1 . Press play. With the system usage meter open, take note of the amount of CPU being used
2. One row at a time, activate a row of sends by highlighting all audio tracks and clicking on a send row with all key modifiers (shift ctrl cmd opt). Log the CPU increase with each send row.

From some tests on different computer systems that myself and some colleagues have access to, here are the early findings:

Intel macs have no issues with this session, and negligible CPU increase when new sends are activated. Consistent results on all versions of Pro Tools.

Silicon macs on versions of Pro Tools 2021.6 and higher get extremely significant CPU hits with each row of aux sends that gets activated. To the extent that the session will crash after four or five rows depending on the computer specs. On 2021.3.1 and lower, there is negligible CPU increase.

In both cases, the problem doesn't seem OS related. It also seems consistent across all Silicon Processors (M1, M1 Pro, etc)

Also of note, just pressing play in the session with no sends on Apple Silicon is using considerably more CPU on 2021.6 and up. Negligible CPU hit on 2021.3.1 and below.


I have filed a ticket yesterday when I first had performance issues with 2022.4, but I think I will file a new one for this specific issue. Would love to hear the results of this across the community, so that we can highlight this problem to Avid and get a fix for it soon.

[Macsearcher]

Tested with MacBook M1 Pro and confirmed.
Same behaviour.
2021.3 runs smooth. Anything later throttles CPU

[Darryl Ramm]

Just a negative confirmation on Intel.

Pro Tools Studio 2022.4 on MacBook Pro 2019 15" running Big Sur, just hums along like a dream. IO buffer size has no effect on CPU use, and I do not expect it to because it's using the fixed size disk IO playback buffer.

Mmm 2021.6 introduce a lot of changes including hybrid engine so hopefully what broke will be easy to find.

One thing you could try is changing the IO buffer size and if that has a radical effect it points suspicion that something got gooched with the disk playback buffer. If I was digging deeper as a developer I'd want to confirm processor affinity is working as expected.

Thanks for finding this and sharing the test session. You should post any relevant support case number here and folks can hopefully make sure it gets attention.

[thebeatless]

Wow, I never thought sends could be part of the lameness of my studio Ultra! Just tested and the CPU usage is hovering between 51 and 60%.

Activity monitor shows 842.6%

[audiogamble]

Thanks for taking the initiative to test this. Support case with Avid is 04410753 . Any colleagues I've shared this info with have gotten pretty consistent results across the board. Intel = fine. Silicon = not .

[bobo mark]

That why I have STRONG believed until Pro Tools goes Apple Silicon native before we buy any new Mac. Acustica Audio M1 native plugins will also made PT instant freeze too.

[Darryl Ramm]

Originally Posted by bobo mark

That why I have STRONG believed until Pro Tools goes Apple Silicon native before we buy any new Mac. Acustica Audio M1 native plugins will also made PT instant freeze too.

You have no way of knowing if this problem would happen on a native port or not. With such massive changes happening you need to expect a long tail of issues that will need to get solved. So test and see if it work for your workflow, and if there are problems try to do stuff like done here to help find issues. The day Pro Tools goes Apple silicon native I expect problems to *increase* at least for a while as folk get to experience the interaction of new native M1 ports of plugins with new Pro Tools.

[bobo mark]

Originally Posted by Darryl Ramm

You have no way of knowing if this problem would happen on a native port or not. With such massive changes happening you need to expect a long tail of issues that will need to get solved. So test and see if it work for your workflow, and if there are problems try to do stuff like done here to help find issues. The day Pro Tools goes Apple silicon native I expect problems to *increase* at least for a while as folk get to experience the interaction of new native M1 ports of plugins with new Pro Tools.

Oh.. Yes.. I always appreciated people do test for us.

[persen]

Same her.
If I tone down the use of sends, suddenly the CPU usage drops significantly (from on the edge 100% to 75%...)

I have made a case and described it briefly and wrote "LINKED TO CASE nr. 04410753".

Is this the right way to link to a case?

Thanks !
Per Einar

[persen]

Hi,

Here are two videos from me using OP's test-session.
One video is with PT 2021.3.1 and the other is with PT 2022.4 STUDIO:

https://www.dropbox.com/sh/qfzwoiov2...roCAu-OTa?dl=0

This is crazy!

Persen