On Sat, 2006-12-16 at 16:21 +0100, Patco wrote:
IOhannes m zmoelnig a écrit :
Hans-Christoph Steiner wrote:
Apple puts good audio hardware in their laptops. I can get 14ms of latency on Mac OS X with Pd without really trying (I just set it to 14ms). I can get down to 11ms if I don't mind clicks when I
operate the
menus and switch to other applications.
as always when it comes to latency and people tell numbers, i have
to
ask my question: have you measured this? how? or was it just
"putting a
number somewhere and assuming that it's the real latency"? how much load do your settings allow?
from my experience, pd's audio backend is the bigger latency problem than the audio hardware, especially on osx/windows, where vanilla pd is using portaudio with pablio, which is unable to get below around 25 ms of round-trip latency (i guess, hans was referring to one-way latencies)
hello, the lowest latency i could get is with the CCRMA low latency kernel patch. On a cheap internal audio card and an USB midi sport 2*2, connecting midi in to midi out gives me a latency measure on [timer] between 15 and 25 ms with the lowest affordable buffers (about 5ms) as
on linux, it's a bit better, but even with wini's alsa implementation, the least round-trip latency it can produce without audio dropouts is around 10ms. using it with smaller buffersizes there are severe timing problems.
with the callback-driven scheduler and the portaudio implementation from devel, it's possible to get below 5 ms on all supported platforms, though.
as for linux, it probably doesn't make any sense to use the rt kernel patches with vanilla pd, as it's internal bottlenecks are a bigger problem than the kernel. and of course, these numbers are without _any_ gui interaction.
hth, tim
-- tim@klingt.org ICQ: 96771783 http://www.mokabar.tk
I must say I find television very educational. The minute somebody turns it on, I go to the library and read a good book. Groucho Marx