[Jack] Cannot start Jack, buffer size too low?

[kujaw]

4.15.5-1-ARCH #1 SMP PREEMPT
I use Cadence.
I have Focusrite Scarlett which I was using yesterday and set buffer size '32'.
With laptop's soundcard I have to set buffer size to at least '64', otherwise it give me error copied below:

Code: Select all

Wed Feb 28 08:38:10 2018: Starting jack server...
Wed Feb 28 08:38:10 2018: JACK server starting in realtime mode with priority 10
Wed Feb 28 08:38:10 2018: self-connect-mode is "Don't restrict self connect requests"
Wed Feb 28 08:38:10 2018: Acquired audio card Audio1
Wed Feb 28 08:38:10 2018: creating alsa driver ... hw:PCH,0|hw:PCH,0|32|2|44100|0|0|nomon|swmeter|-|32bit
Wed Feb 28 08:38:10 2018: configuring for 44100Hz, period = 32 frames (0.7 ms), buffer = 2 periods
Wed Feb 28 08:38:10 2018: ALSA: final selected sample format for capture: 32bit integer little-endian
Wed Feb 28 08:38:10 2018: ALSA: use 2 periods for capture
Wed Feb 28 08:38:10 2018: ALSA: final selected sample format for playback: 32bit integer little-endian
Wed Feb 28 08:38:10 2018: ALSA: use 2 periods for playback
Wed Feb 28 08:38:15 2018: ERROR: JackPosixProcessSync::LockedTimedWait error usec = 14500 err = Connection timed out
Wed Feb 28 08:38:15 2018: ERROR: JackEngine::ClientActivate wait error ref = 2 name = dbusapi
Wed Feb 28 08:38:15 2018: ERROR: failed to activate dbusapi jack client. error is -1
Wed Feb 28 08:38:15 2018: ERROR: JackPosixProcessSync::LockedTimedWait error usec = 14500 err = Connection timed out
Wed Feb 28 08:38:15 2018: ERROR: JackEngine::ClientDeactivate wait error ref = 2 name = dbusapi
Wed Feb 28 08:38:15 2018: ERROR: JackPosixProcessSync::LockedTimedWait error usec = 2900 err = Connection timed out
Wed Feb 28 08:38:15 2018: ERROR: JackEngine::ClientCloseAux wait error ref = 2
Wed Feb 28 08:38:15 2018: ERROR: Unknown request 4294967295
Wed Feb 28 08:38:15 2018: ERROR: CheckSize error size = 0 Size() = 12
Wed Feb 28 08:38:15 2018: ERROR: CheckRead error
Wed Feb 28 08:38:15 2018: Released audio card Audio1

Is this normal, how it should be? Or can I tune something in my system so I don't have to click everytime I switch from external to internal sound card?

[Pablo]

Yes, I would say that setting is way too low.

The lower the latency, the more risk of xruns. Very low latency is only needed in some cases, for example, if you play live with some effects or virtual amplifier (say, guitarix) but even in that case, in my experience at least, 128 periods/buffer is more than enough. Even 256 is OK for my guitar playing.

32 frames/period is ridiculously low and not needed at all and it is no surprise that jack can't start with that setting on the onboard card. On the other hand, it is a good sign that jack even starts with 32 frames on your focusrite but, as said, imho not needed.

Of course, you would learn a lot in the way of trying to start jack with 32 frames on the onboard card but I doubt you could achieve it anyway.