Pianoteq performance


The current settings are not working for me.
When I play the Steinberg very fast, I get click noise and the yellow flash of underpower appears.
The MKII works fine for me.
So I played a little with the settings.
The multicore is set to max right now. When I set it to ON, the yellow flash is gone most of the time.
And I reduced the voices down to 24.

Hence I changed zynthian_engine_pianotec.py at line 87 to

It’s better but still not perfect. Only if I reduce PIANOTEQ_CONFIG_INTERNAL_SR down to 11025, the performance is sufficant. But especially MKII doesn’t sound anymore.

I don’t know, who wrote lines 330 and following and hardcoded -multicore max

I deleted those if/else statements and only called
self.base_command = PIANOTEQ_BINARY


self.base_command = PIANOTEQ_BINARY + " --headless"

I am not sure, if I should check in the changes and would like to hear your opinion / experience.


I’m looking at buying a pianoteq licence so I’ll put that in motion and see what I get


I think this I wrote that lines. At the time of writing (6.01) this was unproblematic and after that a newer version which needed more CPU power was released. Julien from Modartt told me to do so.

I have a Pianoteq-Raspi-3B+ (with an HDMI touch display) which runs also with this optimizations and I never had problems the last year.

Regards, Holger


A little warning: the yellow bolt signals an ELECTRIC underpower: not enough current to support the board as is.

And it should never happens, unless the system is pulled beyond its physical limits (and this is not the case) or something powered from rPI is consuming too much power.


For me, it’s working fine with the current parameters, and i play lot of notes very fast … :sweat_smile:

Of course, if you “abuse” the sustain pedal, you get xruns.

1.) Are you getting the xruns while using sustain pedal or without it?

2.) Are you opening the native Pianoteq GUI? It’s quite CPU consuming and i get XRuns when it’s open, specially with Steinway pianos.

General Rule: Don’t open the native GUI when doing serious playing. Also valid with other engines.



1.) Pianoteq is the only multi-core engine, so RBPi CPU should be consuming more power than normally, when operating a mono-core engine.

2.) If keyboard is being powered by RBPi USB, powering with a separated power source could be a solution.

3.) A bigger/better power source could solve the problem too …



I am working with cpu_isolation for this: 1 core for the GUI and the rest only for Pianoteq (note: not on Zynthian, but on my PIanoteq-only-Rapsi-3B±with-HDMI-touch)


True, but using every available resource does not qualify as “pulling the system beyond its physical limits” :wink:

I have installed a video system with the rPI fully overclocked and every core busy at almost 100%.
It needed a huge heatsink with fan, and even with a 5A power supply, I changed 5 USB cables to find one that worked and showed no yellow bolt.


I am using a dual 3A Meanwell power supply and had only one connected so far.
But the 5" screen and the Midibox connected via USB to the raspi was too much.
Now I connected the Midibox to the second Meanwell outlet and the flash is gone.

Thx @Axeman for the “It should never happen”.


Did improve your Pianoteq performance problems?


Yes, now our experiences seem to be the same :slight_smile:


Holger, could you explain how to do the cpu isolation? I am running a recent Zynthian (3B+) without any other device connected, but I still get occasional overruns.
Best, Chris


I cannot find my scripts… have to search, sorry. But the concept and what to do is written down here.

Regards, Holger


This might be of interest.
When I connected the AudioInjector Ultra, the yellow underpower flash appeared again when playing the Steinberg.
I have a 5Inch screen powered over USB as well.
That’s why I bought a new 6A power supply replacing the 3A.
When I have the MidiBox powered over USB, the flash doesn’t disappear.
Only when I power it directly with the second outlet of that 6A power supply, the flash is gone.
So for all the MidiBox users… don’t power it over USB :slight_smile: