On Thu, Aug 17, 2017 at 11:57 AM, Jaromír Mikeš <mira.mikes@gmail.com> wrote:

What about my 2nd question?
In qjackctrl Settings -> Advanced ... there is a "Priority" option ...
It corresponds to -P cli option
For what is it good and how it should be used?

It's under "Advanced". That means ... if you don't know what it does, don't use it, or adjust it.