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

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MaxDamage
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Joined: 2010-06-02
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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!

LeatusPenguin
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Joined: 2010-12-16
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Have you tried installing a more stripped down desktop environment than unity? Also, are you using the stock kernel? You could try the low latency kernel to see if that makes a difference.

GMaq
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Joined: 2007-12-11
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Hi,

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

MaxDamage
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Joined: 2010-06-02
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@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'.

LeatusPenguin
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Joined: 2010-12-16
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@MaxDamage : I've come across that message before. Your session is making reference to a plugin that was used but it can't find. Either it's not installed on your system or you have a different version installed.

If you want to stick with a Ubuntu based Distro you could try out Dreamstudio to see if it makes a difference.

ahellquist
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Joined: 2011-11-16
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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