Hey all, thought I would share some of my recent discoveries: As demudi 1.2.1 has been lacking a kernel source for awhile and demudi 1.30rc1 refuses to boot on my new hardware I've had to seek alternatives. After reading several threads on using Ubuntu as a music production OS I decided to give Ubuntu 5.10 'breezy' a shot. Installing "realtime-lsm" with module-assistant was easy as pie and I got relatively good latency with the stock kernel, but real improvements came from two things: I decided to give Ubuntu 6.04 "Dapper Flight 3" a run and noticed that #cat /boot/config-2.6.15-4-386 | grep PREEMPT gives CONFIG_PREEMPT=y and has been the same in all the "dapper" kernels I've tried, something that was not enabled in the stable "breezy" kernels. Does this mean the ubuntu guys are looking at releasing a stable kernel with PREEMPT enabled? Anyway the second thing I found was using 'rtlimits' instead of "realtime-lsm". Making use of a small app I found at: http://www.physics.adelaide.edu.au/~jwoithe/ makes assigning realtime access on an app-per-app basis and even user/group basis a breeze. This combination has lowered my latency *under load* to 5.8ms in KDE (Kubuntu is what I installed) and I can squeeze 2.9ms out of it in a very conservative fluxbox or even xfce4 enviroment with no xruns and less than 10% cpu/dps usage (as reported by qjackctl). Most of the good sound apps are available in the repositories as well with the exceptions of Seq24 (conflicting libs) that I easily built from scratch, Freecycle, which I'm still trying to get to compile correctly, and Willem's wonderful DSSI packages. It looks like Ubuntu might have a stable release on the horizon suitable for serious audio work! You are more than welcome to check my blog as well for an up-to-date journal of my ubuntu "studio" experiments and installed software list: http://oktyabr.blogspot.com Best, Jon Hoskins In a world without walls who needs windows or gates? --author unknown
