XRUNS with avlinux 4.0

[agivagan]

Hello everybody,
I like very much avlinux, and I'm trying to test the 4.0, which is great, I like the persistence in case of using it as a live-usb.
The apps are almost complete for my personnal use ( except that I regret to  be unable to compile Qloud, an analysis program : gaydenko.com/qloud . Anyway I use it with gentoo, that is the only distribution to complie it easily)
I miss another app to, but it's easy to compile : BRP_PACU, a smaart replacement.

But my question is : I experienced jack with my audio card vx222-HR and suffer of XRUNS, even with a long latency tweaking ( 2048 frames, and 2 periods at 96000 hz, 48000 hz and 44100 hz).
It seems surprising for me, because when I use Sabayon linux, with kernel 2.6.34sabayon, gentoo based distro, I have no xruns, even if it's a generic kernel.
Did I do something wrong in my tweakings ? Is it because the kernel is more agressive ?
I would like to be able to use avlinux as a live-usb without xruns.
I precise that it happens even with an installed avlinux system ( always on an usb key)
Thanks for reading, and sorry for my bad english, because I'm french and don't speak very good english.

[trulan]

I don't know what is causing your x-runs, but I can offer a few suggestions:
1. Try a different USB port?  It is possible that your USB port and soundcard are sharing an irq - this would cause problems like you are having.  (Are you using Sabayon / Gentoo on a USB key?)
cat /proc/interrupts
Is a good place to start to see if this is a problem.
2. You can try a different kernel - a desktop kernel for AVLinux is here:
(2.6.32 image and headers) http://www.bandshed.net/kernels/
If a generic kernel performs better than the default realtime kernel, something is probably getting messed up with your rtprio scheduling.  Or, it may be possible that your hardware just will work better with a generic kernel.
3. Run jack in synchronous mode - add -S as the first switch in the jack command line, or if you are using Jack Control, add it to the command line like this:  /usr/bin/jackd -S

[varpa]

Could you describe what you are doing in more detail?  For example, are you trying to record using Ardour (or similar)? Are you saving the audio to the USB key?   If so, this is highly non-optimal because (1) USB write speed is very slow compared to a hard disk; (2) also it is generally recommended to write to a different hard disk than is used by the OS.  I had big problem with XRUNS (and even the dreaded "ardour cannot keep up wih JACK" disconnections) until I got 2 2nd disk to write audio to.   Sorry if you know all this already - your post does not specify what you are trying to do exactly

[agivagan]

Sorry for the long time for response.
Actually, I'm trying to have a system with netjack, and or with ssh.
The goal is to control a remote computer, with hard drive and a PCI audio card Digigram VX222-HR. The computer is a megaPC MSI, with Pentium4 3.0 Ghz HT, 2 GB of ram, a RAPTOR sata hard drive (10000 rpm).
For this card I use jackd -d alsa -r 96000 -p 2048 -n 2, for netjack it's the same.
   1. with ssh to simply record some music on my remote hard drive, that works but sometimes xruns. I have'nt try a lot to change latencies values, and I've not tried yet the solution you gave, trulan, but I will do when my holidays end, because the computer is in my locker room at work.
   2. with ssh and as a netjack server, because  I think I will be able to have some effects from my laptop ( which controls the other PC ) in the sound card of the barebone.
    That can make me a travelling system of a lot of things. That's also why I'm trying to have this on usb, because it can be adapted on a lot of computers ( for my part I can also use my home's computer without destroying my wife's OS every week.).
    I also learned on the internet, that now ( since 2.6.32 ) the kernel had realtime capabilities, even generic. I can tell you that a 2.6.34-sabayon is very good with realtime. It supports less low latency than a complete preempt like avlinux's one. The cpu works more with less apps running.
   Thank you anyway for your responses.
cheers