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View Full Version : [ubuntu] [SOLVED] Reduce xruns

ezramorris
May 26th, 2008, 02:37 PM
Hi,
I've just installed Ubuntu Studio (I actually had to install Ubuntu first, then upgrade to Ubuntu Studio). How do I reduced/eliminate the number of xruns on Jack? I am using the realtime kernel, and have followed the instructions here https://help.ubuntu.com/community/UbuntuStudioPreparation .

Thanks in advance.
Stochastic
May 27th, 2008, 01:45 AM
The best method to eliminate xruns is through trial and error. Try different frames/period settings in qjackctl as well as sampling rates, and periods/buffer. Also make sure the Realtime option is checked in qjackctl. Really it's a balance you'll need to find for your computer between latency and xruns (though 1 xrun is too many in most pro circumstances). The only other factor can be the overall load on your computer.
Drunky
May 27th, 2008, 07:22 AM
Make sure you have upgraded to Ubuntu Studio properly before trying to use Jack in real-time. I would suggest using the UbuntuStudio/UpgradingFromHardy (https://help.ubuntu.com/community/UbuntuStudio/UpgradingFromHardy) web page on Ubuntu Help.

You will need the linux-rt to install the real-time kernel or you can't run Jack in real-time. This is paramount if you want to reduce latency or x-runs.
ezramorris
May 27th, 2008, 08:10 AM
Thanks for both your replies. I have the realtime kernel installed, and I knew that there were some options to adjust in qjackctl, but wasn't sure which.

Thank you.
robeast
May 27th, 2008, 10:46 AM
I recently switched my window manager to fluxbox from gnome (with compiz-fusion) and have had much improved performance! Once you have things tuned as well as they can be in jack you may try a light weight window manager to free up some more memory and proc power.
Drunky
May 27th, 2008, 02:03 PM
Here is a web page from Ubuntu Help again:
How to Configure Jack (https://help.ubuntu.com/community/HowToJACKConfiguration)

If you are having trouble with xruns try increasing Frames/Buffer. This will increase latency but I believe it will help with xruns.

Also, I believe increasing Periods/Buffer will help with xruns. Again this may increase latency.
ezramorris
May 30th, 2008, 04:49 PM
... run Jack in real-time. This is paramount if you want to reduce latency or x-runs.

Aha. I always forget this. I seem to assume that if I have the RT kernel installed, that's it. Problem solved. Thanks