Latency in Audio

[sfogar at libero.it]

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 at peabody.jhu.edu>
> To      : "sfogar at libero.it" <sfogar at libero.it>
> Cc      : <pd-list at 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 at 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 at peabody.jhu.edu>
> > > To      : claudio <c.scozzafava at tin.it>
> > > Cc      : <pd-list at 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 at peabody.jhu.edu                           |
> > > | www.peabody.jhu.edu/~karlmac                      |
> > > -----------------------------------------------------
> > >
> > >
> > >
> >
> 
> _____________________________________________________
> | Karl W. MacMillan                                 |
> | Computer Music Department                         |
> | Peabody Institute of the Johns Hopkins University |
> | karlmac at peabody.jhu.edu                           |
> | www.peabody.jhu.edu/~karlmac                      |
> -----------------------------------------------------
> 
> 
>