[LAU] midi keyboards, jackd, low latency

[Paul Davis]

On Thu, Feb 26, 2009 at 4:20 PM, tizo <tizone at gmail.com> wrote:

> Hi there,
>
> Sorry about my previous mail. I was just starting to write a draft
> about the topics I want to ask, and I accidentally push the send
> button.
>
> Well, my goal is to play two midi keyboards, sending the events
> through jackd, to qsynth. My computer is a Laptop HP 550, with HDA
> Intel sound card, 3 GB of memory, and a Core 2 DUO CPU of 1.40 GHz. My
> OS is UbuntuStudio 8.04, with kernel 2.6.24-23-rt.
>
> First of all, I cannot run jackd without xruns, if I configure it with
> 32 frames per period, or less. I am running it as root, with realtime,
> and a priority of 70. As soon as I run it, it starts to count xruns,
> and I am only executing jackd.


32 frames per interrupt is VERY ambitious with an Intel HDA chipset. Its not
impossible but every single part of your system has to be "just right" for
this to work. I would start with a less ambitious goal first, and get some
experience with the setup before trying to get all the way to this latency
level.

moving to USB will likely make things worse. latencies like this are best
accomplished with good, prosumer level PCI audio interfaces.

--p
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.linuxaudio.org/pipermail/linux-audio-user/attachments/20090226/f2123f75/attachment.htm