28 Jan
2013
28 Jan
'13
12:26 a.m.
On Sun, Jan 27, 2013 at 10:32 PM, Len Ovens <len(a)ovenwerks.net> wrote:
On Sun, January 27, 2013 12:20 pm, James Stone wrote:
Latency in 1.1 vs usb 2 shouldn't be significantly different as I
understand it. usb 2 just allows higher bandwidth - so more channels
or 24bit vs 16bit. Just depends on whether the interface is properly
supported in linux.
I have used a USB 1.1 IF on my netbook running at 800Mhz (half speed) and
was still able to run the IF at -p 64 -n 2 (2.67 ms Latency) without
xruns. I did have to back the latency off if I ran too many softsynths or
too many effects, but even double that is not bad. -p 64 with USB 2
devices seems to be the lowest too. I run into memory problems before CPU
use problems in general with only 1G memory :)
.. actually on the Scarlett 2i4, I can start jack with -p 16 -n 2..
but it's not really usable on my ageing PC (Athlon 2500XP 1G RAM)..
lots of xruns.. It will run xrun free at 48k with -p32. push it up to
-p64, and it is pretty solidly stable at 96000 sample rate. Note 2.67
is round trip latency - from sound in to sound out. For midi control
of softsynths, it is half that.
With very short sample sizes, linuxsampler complains that the audio
fragment size is too small though! I think linuxsampler (at least the
version shipped with ubuntu) requires a period of 128 to run
correctly..
James
On Sun, Jan 27, 2013 at 4:05 PM, Saul Rayson
<saul(a)atonic.com> wrote:
For live work, Guitar effects, soft synths, etc. USB
1.1 at 16bit/48k
may
work just fine
My experience with USB audio is limited, but USB 1 on mac, for live
processing, I have found to have unusable latency.