Dorico drops sound occasionally when using an external USB SSD as the macOS (10.15.7) system disk

Dear users and developers.

MacBook Pro machines are too loud, and I moved to my old iMac2013-late with a Fusion drive. To use the machine more comfortably, I booted the system from an external SSD. The performance is better, but Dorico drops sound occasionally when switching application by pressing CMD + tab while Dorico is playing the score.

Does it occur from macOS-side or Dorico-side?

Thanks in advance!

Lots of factors here: the quality of the external drive’s interface; how much memory you’ve got (and whether switching apps requires swapping in/out), etc.
If it’s not generally happening for most users when switching apps, then I doubt it’s something that Dorico can influence or improve on.

I’m surprised that the mechanical drive is quieter than an MBP?

The following is my iMac’s specification:

  • iMac (27-inch, Late 2013)
  • 3.5 GHz Quad-Core Intel Core i7
  • 32 GB 1600 MHz DDR3
  • NVIDIA GeForce GTX 780M 4 GB
    <- with 2 external monitors:
  • 2048*1152,
  • 1920*1200,
  • 3840*2160
  • SSD speed:
  • reading: > 330 MB/s
  • writing: > 350 MB/s

Currently, about 13 GB memory is free.
I am running Dropbox, Onedrive, Parallel Desktops (the virtual machine is suspended.)

There is no related phenomenon between fan speed and sound drop.

I currently have no sufficient experience with other applications. Most of my applications should firstly be synchronised from Dropbox or Onedrive. It requires about one week or ten days.

The problem seems to occur only in Dorico, and the length of the sound drop related to the buffer size of Core Audio Device Settings in Dorico:

Dorico audio engine seems not to process sound occasionally the required task in the amount of buffer size.

I have tested if the following applications drop sound when using USB3.0 SSD as a macOS booting disk, but only Dorico drops sound:

  • SuperCollider
  • Logic Pro
  • Ableton Live
  • Music
  • VLC

I would be thankful if other users share their own experiences using Dorico while the machine is being run from Thunderbolt storage and USB storage.

Changing the USB ports of the devices attched to the iMac does not improve the problem.

You say that “Dorico drops sound occasionally when switching application”. How much of a problem is that really to you?
We understand it is a problem if drop-outs occur when only Dorico is running, but under this circumstance, we can not guarantee continuous audio in every case,
especially when running from external disk. There are so many factors playing in here, size of project, used VST instruments, audio settings, just to mention a few.
Not even talking about the hardware config. So we can’t guarantee seamless audio under every situation with any configuration, it’s impossible.

Hello Ulf, Thank you for your answer.
I encountered the problem only when switching applications when writing this thread.
However, Today I experienced that Dorico drops sound, even when working within Dorico. It occurs relatively often.

I will test further, but I could not find any solution, I should not boot from a USB storage…

I also should test if it occurs only when using Dorico.t seems so, but not sure. I need more experiences.

What kind of projects do you work in average with, i.e. how many players, how many VSTinstruments and which ones?

It differs from projects to projects, from small ensemble to large orchestra.

In this week, I did a project for six violas and two pianos. Six violas and one piano are allocated to NotePerformer, and one piano is assigned to Kontakt to use an electroacoustic music effect. Dorico drops sound even when a single instrument plays sounds when working on this project file.

Now, I am working for a large orchestra with harp and some small percussion. Dorico uses five VST slots: four slots for NotesPerformer and one slot for Kontakt.

What if you make backup copies of those projects and experiment with them? E.g. the 6 viola 2 piano piece, what if you use only NP or only Kontakt in it? You know, I want to find out if the problem is specific to a certain VSTinstrument.
Also, what is the most simple project setup where the problem happens? You could fill it with arbitrary notes and post the project here, so we can try to reproduce.

I removed Kontakt from the VST slot, used only NotePerformer. However, the problem occurs still. I only heard the first moment where only one piano is played back.

Regretfully, I the most simple project setup is a piece for woodwind quintet. I used only Noteperformer. This project has also the same problem.

I would say the number of staff does not matter… Hm…

The problem seems to be simply an overloaded in writing and reading data.
Dropbox finished synchronisation and Onedrive does still synchronisation. Now, Dorico drops sound less than a few days ago.

I am still curious why it does occur only in Dorico.
Does macOS give less priority to Dorico in Data transmitting (storage -> buffer -> CPU)?
Dorico does not drop sound when system booted from internal fusion drive…

I cannot judge it because I do not know if NotePerformer send all samples to buffer when loading NotePerformer or not.

I cannot tell either. Could be the VSTinstrument, could be the audio engine, the hardware…could be so many things. Out of scientific curiosity it would be interesting to find out, but given that we have so many other things to do, I’m inclined to say, that we are not going to investigate on this. I hope for your understanding.

It is no problem, Thank you!