Found this in the archives, maybe it is somewhat similar: in the early Raspberry Pi days core switching seemed to be a problem for Pd and it could be solved by using 'taskset'. See:
https://lists.puredata.info/pipermail/pd-list/2015-02/109189.html
The CPU switching problem went away 'by itself' after a Raspbian update, but it was probably hardware specific.
On Wed, Jan 31, 2018 at 12:31 AM, katja katjavetter@gmail.com wrote:
What happens when running Pd with option -nosleep? I vaguely remember having problems with CPU scaling which could be 'resolved' with that option. People smarter than me pointed to other solutions where you could reserve a specific core for the Pd process. But I'm unable to retrieve that information.
On Wed, Jan 31, 2018 at 12:08 AM, Roman Haefeli reduzent@gmail.com wrote:
On Die, 2018-01-30 at 23:31 +0100, Dan Wilcox wrote:
I agree. I recorded 8 channel multitrack from Pd to Ardour using a single core Thinkpad back in the day with no drop outs.
You could try running Pd with a different nice level. Even though it has "realtime priority" it sometimes helps to cue the scheduler a little more directly.
'pd -rt -jack' runs with a nice level of 0, so does jackd and ardour. I tried giving it higher priority up (or should I say: down?) to -10, but it didn't change the situation. Also, it seems to me that it's not a problem of priorities between several processes. The fact that burning CPU cycles with _another_ process helps makes me think the problem rather is that resources are not made ready quickly enough.
Roman
On Jan 30, 2018, at 11:21 PM, pd-list-request@lists.iem.at wrote:
Interestingly, setting CPU scaling governor to performance is not enough for Pd (it is for other applications, though). When doing that for each core, they all run at maximum speed. However, it doesn't help with making Pd glitch free. I really have to put some load on them.
This confirms what I suspected for while now: The advanced power saving features of modern CPUs don't really help for realtime audio.
I wonder what softwares like Ardour do differently to not fall victim of aggressive power saving.
Having a constantly running fan is also not an ideal situation. I don't care about increased power consumption at this point. Maybe there is a less invasive way to keep the CPU busy?
Dan Wilcox @danomatika danomatika.com robotcowboy.com
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