High CPU utilization with 20+ tracks

[unfa]

I know Zyn is big and having 25 instances makes an impact, but hey - there are only 4-5 of them playing simultaneously at all times - why do the rest drains my CPU time when they are not used?

It feels like every new instance of ZynAddSubFX adds some CPU drain even when it's not playing any notes. I wonder if it's really ZynAddSubFX responsible the performance impact or is it LMMS.

I wonder if something could be done about this.

The project I've expirienced this issue in is here:
https://lmms.io/lsp/?action=show&file=6599

Let me know if you experience this performance impact too.

[tresf]

The project I've expirienced this issue in is here unfa-Spoken.mmpz

Fixed. :)

Seriously though, depending on the back-end, I can agree that we have very high CPU utilization on your spoken track regardless of the backend being used and speaks more to need for overall resource improvements rather than a specific plugin. I can get the software to run really slow and take up all of my CPU just adding TripleOscillators and piano rolls, so from my findings, the Zyn stuff you are observing is likely to be core-performance related.

[tresf]

Oh... and here're some test results from an unlikely thread title: #1600 (comment)

[unfa]

Lol, my track has become a benchmark :D How awesome!

@tresf
I'm glad it's rather LMMS issue, because we can do something about it.

My first idea is: could LMMS dynamically "stop" any instrument/effects plugins from operation if they have no notes played or sounds above (ror example) -80dB level coming out?

[tresf]

@unfa,

No idea what can be done to help this. It will take some research. 👍

[fundamental]

@unfa
I'm not sure how much is lmms and how much is zyn, but I do remember seeing that the internal overhead on non-playing standalone zyn was higher than I would like it to be.
Lowering that overhead is somewhat complicated due to the existence of always on effects, but some improvements can likely be made (and the 2.4.4->2.5.0 upgrade should eliminate some of the overhead).