Re: [LAU] linux-rt & presonus 1818VSL

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Fero Kiraly <fero.kiraly@...>
Cc: linux-audio-user@lists.linuxaudio.org <linux-audio-user@...>
Date: Tuesday, July 2, 2013 - 5:49 pm

--001a11c36be8d37a7e04e08af6f4
Content-Type: text/plain; charset=ISO-8859-1

On Tue, Jul 2, 2013 at 5:53 PM, Fero Kiraly wrote:

There's a lot more to removing Xruns from a system than just the kernel and
JACK settings (although they are very important :)

Known things that need to be done:
-Interrupt requests of your hardware must be prioritized (rtirq script
helps here)
-Interrupt thread handlers (on RT kernel) must be prioritized
-Thread priorities must be checked for JACK itself

Some other things to look into are:
-CPU scaling (causes Xruns here, although others say it works fine)
-WiFi (must be disabled here: "iwconfig wlan0 txpower off", not just
disconnected)
-Graphics chip drivers (I'm using a standard xf86-video driver for my ATI
HD2400XT)

That's a good start anyway: If I find some time, I'll write a quick post on
tuning an Arch system for maximum low-lat RT performance.

> My aim is to get as low latency as possible.
Please specify... How low is low :D I've achieved 0.3ms at 96kHz, running a
CPU stress test on each core without Xruns, so I'm pretty happy with
that... since the hardware (Echo Indigo DJ PCMCIA) can't handle any lower!

> but none of them was without xruns when running:

PD is a bit of a xrun hog on my machine here: not bashing PD, I probably
don't have it set up with ideally. But perhaps try running eg Ardour on its
own for testing purposes? Or another simple app which isn't as dependent on
the "patch" that's loaded..?

HTH, -Harry

--001a11c36be8d37a7e04e08af6f4
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

On Tue, Jul 2, 2013 at 5:53 PM, Fero Kiraly <fero.kiraly@gmail.com> wrote:>=
I have some troubles - read xruns - with this setup:There's a lot =
more to removing Xruns from a system than just the kernel and JACK settings=
(although they are very important :)
Known things that need to be done:-Interrupt requests of your hardw=
are must be prioritized (rtirq script helps here)-Interrupt thread hand=
lers (on RT kernel) must be prioritized-Thread priorities must be check=
ed for JACK itself
Some other things to look into are:-CPU scaling (causes Xruns here,=
although others say it works fine)-WiFi (must be disabled here: "=
iwconfig wlan0 txpower off", not just disconnected)-Graphics chip =
drivers (I'm using a standard xf86-video driver for my ATI HD2400XT)
That's a good start anyway: If I find some time, I'll write a q=
uick post on tuning an Arch system for maximum low-lat RT performance.<=
br>> My aim is to get as low latency as possible.Please specify... H=
ow low is low :D I've achieved 0.3ms at 96kHz, running a CPU stress tes=
t on each core without Xruns, so I'm pretty happy with that... since th=
e hardware (Echo Indigo DJ PCMCIA) can't handle any lower!
=A0> but none of them was without xruns when running:> pd - p=
lugins - ardourPD is a bit of a xrun hog on my machine here: not ba=
shing PD, I probably don't have it set up with ideally. But perhaps try=
running eg Ardour on its own for testing purposes? Or another simple app w=
hich isn't as dependent on the "patch" that's loaded..?
HTH, -Harry

--001a11c36be8d37a7e04e08af6f4--

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[LAU] linux-rt &amp; presonus 1818VSL, Fero Kiraly, (Tue Jul 2, 4:53 pm)
Re: [LAU] linux-rt & presonus 1818VSL, Harry van Haaren, (Tue Jul 2, 5:49 pm)
Re: [LAU] linux-rt &amp; presonus 1818VSL, Robin Gareus, (Tue Jul 2, 6:27 pm)
Re: [LAU] linux-rt &amp; presonus 1818VSL, Jeremy Jongepier, (Wed Jul 3, 8:09 am)
Re: [LAU] linux-rt &amp; presonus 1818VSL, Robin Gareus, (Wed Jul 3, 8:32 am)