New subject: Latency in Audio

6 Mar 2001

      Hi Karl,
this is only partially true, I'm using Pd with standard (Rme) audio 
drivers, of course !
And Karl, what about a pd porting to OS X when it will be ready, aren't 
you working on Apple hardware ?
Cheers
Alessandro Fogar
...
---------- Initial message -----------
From    : Karl MacMillan karlmac@peabody.jhu.edu
To      : "sfogar@libero.it" sfogar@libero.it
Cc      : pd-list@iem.kug.ac.at
Date    : Mon, 5 Mar 2001 11:44:11 -0500 (EST)
Subject : Re: Latency in Audio
On Fri, 2 Mar 2001, sfogar@libero.it wrote:
...
Hi all,
in my experience Pd works much better on Win2k than on Win98.
This is not surprising since you are using ASIO - the scheduler is
supposed to be significantly more stable under 2000, but the standard
audio drivers have additional buffering (in the range of 30
milliseconds).
...
ASIO circumvents these additional buffers allowing you to take
advantage
...
of the better overall performance of 2000.
Karl
...
Using Asio and Rme Hammerfall I could obtain good latency (under 50
ms)
...
...
with Cubase.
Under Win2k the best should be to use a multiprocessor Pc.
And remember you have to carefully look at the interrupts (perhaps
installing the standard PC Hal helps).
Consider that you'll not be able to achieve good results using the
SB
...
...
Live with standard drivers and Pd (I tried).
With The Hammerfall and Pd the latency is acceptable but not ideal.
Don't know about the Terratec.
We'd need the Asio interfacing but is it worth ?
Wouldn't it be better to use Linux or (possibly in the future) Apple
Mac OS X ?
Cheers
Alessandro Fogar
...
---------- Initial message -----------
From    : Karl MacMillan karlmac@peabody.jhu.edu
To      : claudio c.scozzafava@tin.it
Cc      : pd-list@iem.kug.ac.at
Date    : Thu, 1 Mar 2001 22:15:40 -0500 (EST)
Subject : Re: Latency in Audio
Claudio,
You are not going to do very well trying to get better results
out of
...
...
...
Windows ME / 2000 until PD supports something like ASIO.  Even
then, I
...
...
...
don't think that the results are going to be that good.  In some
tests
...
...
...
that I did recently the best full-duplex performance I could get
out
...
...
of
...
Windows ME was 73ms and Windows 2000 was 120ms - this was using a
minimal
...
'ideal' application with the MME interface.  This was on a 700mhz
PIII and
...
a 933mhz PIII respectively.
Many companies have been advertising much better results under
Windows and
...
I have to say it seems that either a) these results represent
something
...
other than real world performance or b) the app runs almost
entirely
...
...
as a
...
kernel driver (gigasampler being the best example of this).  If
you
...
...
really
...
want good latency you should try Linux or Irix.  For the same test
that I
...
mentioned above I got latencies below 3ms using Linux 2.4.1 and
Alsa -
...
...
...
this is using standard programming interfaces and the same
computer
...
...
as the
...
Windows 2000 test.  If you have to use windows, I would suggest
downgrading to windows 98 as it is slightly better.
Karl
...
Hi,
       I've some problems with the latency in PD's Audio in/out.
    I use PD under Windows ME and Win2000 and works very well
(in
...
...
Win2K midi timing is more stable), but I've some problems to use it
for
...
...
my works in real time. I must use it for very little patch
(filtering,
...
...
ring modulation ...), but the latency is about 300ms.
...
...
I run it on a Athlon Th. 800 Mhz, 256 Ram, HD IBM 30Gb,

audioCard SBLive.
...
...
How can I reduce the latency? I will buy a Terratec 24/96, 

so I
...
...
hope to reduce the latency time.
...
...
Can someone give me some councils?

With my best regards
Claudio Scozzafava

| Karl W. MacMillan                                 |
| Computer Music Department                         |
| Peabody Institute of the Johns Hopkins University |
| karlmac@peabody.jhu.edu                           |
| www.peabody.jhu.edu/~karlmac                      |

| Karl W. MacMillan                                 |
| Computer Music Department                         |
| Peabody Institute of the Johns Hopkins University |
| karlmac@peabody.jhu.edu                           |
| www.peabody.jhu.edu/~karlmac                      |