[PlanetCCRMA] Low latency kernel?

Luis Garrido luisgarrido@users.sourceforge.net
Mon Dec 5 09:06:01 2005


I am using an USB 1.1 Edirol UA-25 interface with the following jackd
parameters:

 /usr/bin/jackd -R -P65 -dalsa -dhw:UA25 -r48000 -p256 -n3

This means a latency of 16 ms, which I deem adequate for live
triggering of softsynths.

I get occasional xruns when firing up applications or when I use a lot
of CPU (e.g., a fast harp glissando with long samples and no polyphony
limitation).

For stereo live recording (48 KHz, 24 bit) where latency is a
non-issue, buffers of 4096 frames instead of 256 keep me on the safe
side.

If you have a modern CPU with frequency scaling (I don't think so,
since your laptop doesn't have firewire) be sure to set your CPU
frequency to a fixed value (normally the max), otherwise jackd goes
nuts.

HTH,

Luis