Paul Theodoropoulos via time-nuts writes: > I've also found that my Raspi's give the best results with board temp > right around 60°C. However, I found that the 'CPU as heater', while it > does help dramatically compared to nothing at all, it introduces a lot > of jitter on its own. Much better results by keeping them in an > insulated enclosure in a relatively stable location (for me, a > closet!), and 'tuning' the insulation as needed to balance venting > against retention.
Well, I have jitter (PPS timestamps) within ~2µs and the occasional "hair" that goes out to about 30µs. The distribution is a little bit wider on the three systems that are loaded with extra server tasks, but not much. The thing to note is that you need to boot with "nohz=off", set a fixed frequency as high as possible and use an interval timer for controlling the CPU load (I use all four cores as workers and adjust them at 40Hz). [I can post plots, but at ~500kiB I think I should rather ask for permission first.] Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Waldorf MIDI Implementation & additional documentation: http://Synth.Stromeko.net/Downloads.html#WaldorfDocs _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.