Hmmm. Best results so far are by unticking RT completely from jack, and using only 44.1kHz. Guitarix does not like 48kHz very much.
Running without RT makes it possible for me to lower buffer size to 128 and even 64. But at 64 I get xruns from every event on the screen, such as mouse movement, or what else the desktop is communicating. I can hear that guitarix+jack are able to deal with buffers this low, but get interrupts from every desktop event. This is where priority could be nice.
I tried to give both jack and guitarix RT priority, but that froze up the machine immediately.
Edit: Actually I can push the buffer as low as 16 with no noticeable difference from 64. But I still get these annoying interrupts from desktop events.
Edit, edit: Even better results now. By ticking RT on on jack, but assigning only default priority, setting frames/period to 64 and starting jack with qjackctl, I can now start guitarix as a client with latency 16, no glitches, very low latency, and no freezing up the kernel!
Last edited by Frank Carvalho
on Sun Dec 04, 2016 9:36 pm, edited 1 time in total.
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.