Just the other day I found information that suggests that the current kernel, used by VortexBox, offers the realtime features that were not available in older kernels:
Originally Posted by dpaws
Source : http://wiki.linuxmusicians.com/doku....210dcdf2cc362c
Kernels >= 2.6.31 seem to work pretty good without RT patch, also for real-time pro audio usage. It's not strictly necessary anymore to install a real-time ('rt') kernel to get good results. Although the best results are still expected when using a real-time kernel. Try it, test it and decide for yourself.
In the pre-2.6.39 kernel era rt kernels were indeed necessary in some cases where sound devices were sharing IRQ's with other peripherals. With the rt kernel and the rtirq script you could prioritize IRQ threads but since 2.6.39 it is possible to use the rtirq kernel with a generic kernel and the threadirqs kernel option.
However, I do notice a difference when I apply a few modifications:
vm.swappiness = 10
fs.inotify.max_user_watches = 524288
@audio - rtprio 90
@audio - memlock 512000
@audio - nice -19
These are only a few lines to edit.
/usr/bin/chrt -f -p 99 $(/usr/bin/pgrep softirq)