high dsp load causing xruns in recent ubuntu distros (studio, kx-studio)

Hey there!

I tried moving from ubuntu studio 10.04 LTS to 12.04 LTS recently because i wanted to take advantage of the device support of the new ffado drivers.

I stumbled upon performance issues with 12.04:
An Ardour session I recently created with 10.04 that uses quite a number of tracks and plugins now causes dozens of xruns because dsp load is constantly over 90% up to 100%. Dsp load is around 1-3% in idle mode.

The same session with the same jack settings and the same interface worked fine on ubuntu 10.04 with approx. 50-70% of dsp load and only very few xruns.

I already found out that ubuntu studio 12.04 seems to have pulseaudio implemented in a different way which causes quite a lot of cpu load. So, completely deinstalling pulseaudio and LADI reduced the dsp load quite a bit but it’s still far from being stable causing lots of xruns.

I also tried using kx-studio but it has the same issues.
(av-linux seems to perform better but i can’t get my old ardour sessions to work with it)

Does anyone of you know other tricks to increase performance with ubuntu?

Thanks very much!

Hi,

What is the issue with the older Ardour sessions in AV Linux? What is the error message?

Hi

I am running a non tweaked dreamstudio of latest version for family internet usage and just for goofing around with audio. No serious audio projects on that machine. I belive the performance is not that you would expect from such hardware. Get x-runs and lag all the time with just 3-4 tracks of midi and no audio.
The box is a Dual core 4Gigram Intel onboard gpu using internal soundcard. Standard kernel running RT

Maybe the preconfigured irq tweaking in AV is what gives the huge improvement ?
The debug overhead in Ardour Beta 5 might also be adding trouble ?

Running 256/3 will usually get things better but for realtime it does not perform. I have not tried avlinux on that machine but previous versions of av have been a huge improvement regarding performance.

I am sad AV is end of life though.

/Ah

@LeatusPenguin:
UbuntuStudio already comes with XFCE desktop and lowlatency kernel. I also tried out other kernels (rt and preempt) but no difference there.

@GMag:
It won’t connect to jack. Also the mixer is like frozen. I can highlight plugins but I can’t move/add/delete anything.
When opening these sessions the log says:

[ERROR]: Found a reference to a plugin (“33919”) that is unknown.
Perhaps it was removed or moved since it was last used.
[WARNING]: insert could not be created. Ignored.
[ERROR]: Found a reference to a plugin (“33919”) that is unknown.
Perhaps it was removed or moved since it was last used.
[WARNING]: insert could not be created. Ignored.
[INFO]: Loading session /media/data/steffen/musik_shared/ardour/recording/wall_mix1 using snapshot wall_mixedit3 (1)
Loading history from ‘/media/data/steffen/musik_shared/ardour/recording/wall_mix1/wall_mixedit3.history’.