On Jan 30, 2018, at 9:25 PM, pd-list-request@lists.iem.at wrote:

Date: Tue, 30 Jan 2018 21:25:26 +0100
From: Roman Haefeli <reduzent@gmail.com>
To: Pd-List <pd-list@lists.iem.at>
Subject: Re: [PD] glitches when streaming UDP
Message-ID: <1517343926.2187.14.camel@gmail.com>
Content-Type: text/plain; charset="utf-8"

On Die, 2018-01-30 at 16:38 +0100, Dan Wilcox wrote:

Is it running with the *same* OS and settings?

As far as I can tell: yes. Same OS (Ubuntu 16.04), same Kernel (4.13.0-
32-lowlatency), both tuned so that "realtimeconfigquickscan" doesn't
complain anymore. This includes configuring /etc/security/limits.conf,
adding user to audio group, making high-precision timer /dev/hpet und
realtime clock /dev/rtc readable by members of audio group, etc. I get
stable performance with Ardour with the same qjackctl settings, with
built-in soundcard, but also with external USB sound interface on BOTH
machines.

It might be a scheduling issue with the kernel, realtime settings,
crappy networking driver, etc. 

I thought about that, too. But why does it affect only Pd? On the
"troubled" machine - where everything else runs supersmooth - this
setup suffers a couple of glitches per second (jack routing):

mpv -> Pd running [adc~]-[dac~] -> system output

The probable causes you mentioned would affect other audio softwares,
too, wouldn't they? 

The Pd version doesn't seem to make a difference...

Anyway, thanks for your thoughts.

Roman