[PD] MIDI In-to-Out Latency

Sun Jun 6 20:03:28 CEST 2010

I've used the M-Audio 2496 (PCI) as well as RME HDSP. At the moment I'm
using the onboard soundcard of the mainboard which is a Realtek ALC889 (8ch
with SPDif out).

No problem with either one.

I don't like USB soundcards because latency is quite bad and they have a lot
of overhead plus a tendency to drop outs.

I have no experience with firewire cards on Linux but on windows the drivers
are not nearly close to the PCI RME drivers. I also have a focusrite
"saffire pro" which is a toy compared to the HDSP. The RME drivers are way
(!) behind on Linux compared to the Windows drivers. In general it seems
like Linux has a better audio system but Windows has better soundcard
drivers. So you'll end up with a similar result once everything is
optimized. On Linux ALSA drivers don't work for me at all. OSS is my
personal choice. ALSA only works with the -nosleep flag on here. And that
option is still not as good as OSS for my systems.

So there are many things that add up to span from unusable to absolutely
great. Low latency needs a certain combination of the right hardware
components. Depending on your mainboard chipset things can change
dramatically. I prefere Nvidia and AMD chipsets. And I stay away from VIA
(maybe this has changed by now?).

About hyperthreading: yes it can be disabled - and you still get 50% of the
CPU. Doesn't help anything. If you use Pd you should go for AMD on Windows
and Linux. On Mac you don't have that choice, of course. I'm wondering what
the developers would say about that topic?

Ingo

________________________________________

Von: anewkindofblue at gmail.com [mailto:anewkindofblue at gmail.com] Im Auftrag
von Pedro Lopes

Gesendet: Sonntag, 6. Juni 2010 19:22

An: Ingo Scherzinger

Betreff: Re: [PD] MIDI In-to-Out Latency

By the way Ingo Scherzinger, probably non-related but what RME do you use in
Ubuntu? I need to purchase a soundcard compatible with Linux (since my Motu
U.mk3 is a pain...) and looking for ideas... 

:)

The ideal card would use USB2.0 and have a minimum of 4 in + 4 out, low
latency, ASIO on Windows, and Linux support - the price is the tough part...
I really wish that MOTU would consider opening drivers for
Linux...bastards.. the card is really good and has internal DSP with great
sound results in my consideration.

thanks if you can share some thoughs about your soundcard+linux setup, Pedro
On Sun, Jun 6, 2010 at 6:19 PM, Pedro Lopes <pedro.lopes at ist.utl.pt> wrote:

Hyperthreading can be disabled - I never tryed it myself - but its in BIOS
advanced options for most computers/motherboards I've seen. 

Depending on the situation that can be either good of bad, If you only run
one intensive cpu program (i.e.: one instance of PD) is good to give a full
cpu to it, but if you run for instance Renoise (which for me is cpu
intensive) and Pd, disabling hyperthreading will result in even more buffer
glitch. I think some game folks used to disable hyperthreading in intel's p4
and get better rates than with it turned on, just to serve as a mere example
- but then again Software Engineers would argue that this is just a matter
of how threaded the programs are, and how they make good use of that. 

Best regards,

Pedro

On Sun, Jun 6, 2010 at 6:08 PM, Ingo Scherzinger <ingo at miamiwave.com> wrote:

Looks like there are some problems with the soundcard drivers.

I'm running very heavy patches with 3 ms. Both on Windows XP and Ubuntu.

Audio and MIDI.

However, on Windows I am using a RME HDSP card which has very good ASIO
drivers. Don't forget to set system options to "background tasks" (very
important!).

I also noticed that in general Intel CPUs are pretty bad for Pd since they
use hyperthreading which makes Pd see two CPUs and uses only 50% of one
core. AMDs are twice as efficient because Pd uses the entire core.

Ingo

> cyrille henry wrote:

> > but since you don't like this, you should : in pd / startup add in 

> > "startup flags" :

> > -noaudio -audiobuf 0 -mididev 3

> > than : "save all setting" and it should work for next reboot...

> >

> 

> That's fine but what if you want to trigger sound with the MIDI input?

> I've been trying some settings and find that if I set the delay less 

> than 100ms the MIDI delay goes up to about 500ms, if it works at all.

> 

> I usually only use Pd on WinXp to generate background tracks since the 

> latency is so awful compared to linux.

> 

> Martin

_______________________________________________

Pd-list at iem.at mailing list

UNSUBSCRIBE and account-management ->
<http://lists.puredata.info/listinfo/pd-list>
http://lists.puredata.info/listinfo/pd-list

--

Pedro Lopes

contacto: jazz at radiozero.pt

website:  <http://web.ist.utl.pt/Pedro.Lopes>
http://web.ist.utl.pt/Pedro.Lopes 

-- 

Pedro Lopes

contacto: jazz at radiozero.pt

website:  <http://web.ist.utl.pt/Pedro.Lopes>
http://web.ist.utl.pt/Pedro.Lopes 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20100606/4940170d/attachment.htm>