Also, you could try to use the zynthian with no device attached, only using the zynstep to see if it still gives you XRuns.
As @Baggypants says, some engines will generate more XRuns than others. Also, it’s not strange to have some sporadic XRun, speciallay when creating/deleting layers or adding/deleting FXs. That’s perfectly normal while you don’t ear the XRuns when playing.
Regards,
Okay, I performed a few more exercises on my Zynthian today and I can highlight just using the midi ports alone and excluding the USB ports completely greatly reduced the problem occurring, I had a single warning message in the last 6 hours which may have occurred under the circumstances you’ve mentioned. My during this test my Boss DR-880 was providing a bass pattern at midi-ch2 and drum pattern at midi ch10 for 3 hours without issue, my Roland PC-160 (midi only) keyboard was attached but not used. I will repeat the procedure tomorrow via the USB ports. MPK mini (being a USB only) alongside my Yamaha ND32 wasn’t attached but will be introduced?
Are any of the midi equipment set to send MIDI clock out?
No. This is what I’ve discovered today, I simply left my Zynthian switched on overnight! Midi ports connected but nothing else is on (which implies it’s generating it itself).
– Logs begin at Mon 2021-02-22 16:22:57 GMT. –
Feb 22 16:23:03 zynthian startx[491]: lilv_world_load_bundle(): warning: Replacing version 2071.7 of http://gareus.org/oss/lv2/b_whirl#extended from <file:///zynthian/zynthian-plugins/lv2/b_whirl.lv2/>
Feb 22 16:23:03 zynthian startx[491]: lilv_world_load_bundle(): note: New version 2071.11 found in <file:///zynthian/zynthian-plugins/lv2/b_whirl/>
Feb 22 16:23:03 zynthian startx[491]: lilv_world_load_bundle(): warning: Replacing version 2071.7 of http://gareus.org/oss/lv2/b_whirl#simple from <file:///zynthian/zynthian-plugins/lv2/b_whirl.lv2/>
Feb 22 16:23:03 zynthian startx[491]: lilv_world_load_bundle(): note: New version 2071.11 found in <file:///zynthian/zynthian-plugins/lv2/b_whirl/>
Feb 22 16:23:03 zynthian startx[491]: lilv_world_load_bundle(): warning: Ignoring bundle <file:///zynthian/zynthian-plugins/lv2/b_synth.lv2/>
Feb 22 16:23:03 zynthian startx[491]: lilv_world_load_bundle(): note: Newer version of http://gareus.org/oss/lv2/b_synth loaded from <file:///zynthian/zynthian-plugins/lv2/b_synth/>
Feb 22 16:23:04 zynthian startx[491]: libjackpeak registering as ‘jackpeak’.
Feb 22 16:23:04 zynthian startx[491]: libjackpeak created input ports
Feb 22 16:23:48 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 22 16:23:48 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 10:16:57 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 13:10:29 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 13:10:29 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 13:10:29 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 13:10:29 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 13:19:51 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 14:06:34 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 14:06:34 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 14:16:44 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 14:16:44 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Feb 23 14:16:44 zynthian startx[491]: WARNING:zynthian_autoconnect.cb_jack_xrun: Jack Audio XRUN!
Can you use the terminal in the web-ui, or ssh in, to run top and see if there are processes using a lot (like more than 20%) of cpu?
Still got the issue, only audio and midi ports used, no usb ports connected?
What does this tell you?
Some of the engine/FXs you are using is taking all the CPU. It seems that you have the VNC Server enabled, so the first thing you should do is disabling it. Most probably, some plugin’s GUI is causing the problem.
After disabling the VNC Server, try again …
Second, please, could you specify what combination of engines & effects are you using?
You could send the snapshot too 
IMPORTANT NOTE FOR ALL ZYNTHIANERS!! Please, don’t leave the VNCServer enabled by default. If you do so, you are calling for problems. Plugin’s native GUIs are not well tested on zynthian and for sure, more than one will cause performance problems. Only enable the VNC Server when needed, and disable it when you don’t need it.
Regards,
