I think I've got it :-) Muchas gracias to Joakim Hernberg, who posted the jack2 profiling document. I read it about five times, trying to ponder what my first step might be given that info. It discusses two major modes of jack2: the default, which is asynchronous, and another, which is synchronous. Under asynch, my stress-test yields zero xruns (or close) at 5.3 ms (as reported in Qjackctl); but under synch, my last two tests say kosher at 0.667 ms *grin* Shocking. That synch makes a whole lot of difference. I can just imagine jack2 jockeying all four CPUs to make that happen :-) I'll be doing a lot more stress-testing to prove it, but for right now, frames/period are 64, sample rate 192000, two periods/buffer :-) :-) I praise the Lord, and I thank everyone for the help! J.E.B. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user