Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
Folks, Thanks for all the help. I've put up a simple Web page showing the program and its results here: https://www.satsignal.eu/ntp/Raspberry-Pi-ntpheat.html A good gain on that Raspberry Pi in a centrally heated room and nearer the radiator than it should be. Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
From: folkert You can also keep the GPU busy. That'll work as well with the bonus that the main cpu stays mostly idle (iirc) for other tasks. https://vanheusden.com/ntpheat.cpp requires https://github.com/mn416/QPULib === That's neat! Thanks! Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
[sorry for breaking the threading, I'm replying from the list archive since gmane.io does not have this list anymore] Hi David, [ntpheat] > I didn't know about that program and I'd like to try it here. A neat idea. > Is it available stand-alone - ready to run? I could compile it here given > the source, but not if it has dozens of dependencies on NTPsec, which I > don't use. It's actually an implementation of a suggestion by me a few years back, however it doesn't take into account that the CPU temperature can not directly translate into the crystal temperature and it does not regulate even the CPU temperature very well. I've since refined that concept to use the CPU load and CPU temperature to correlate that back to the actual crystal temperature. It takes a bit of time to tune it up correctly, but it turns out that the rasPi I have are all very similar, so if you start with a generic set of constants you don't really make much of an error. I've posted results of that setup last year on July 22nd: http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2019-July/097218.html The control loop is a Perl script that needs two standard Debian modules installed on top. If you're interested, you can mail me directly. I have two TinkerBoard that have better clocks (less noisy on the medium term) and I can usually keep them within 5ppb over a week or around 1ppb per two days (with a linear drift removed). These however need a custom kernel since the turnover point for their crystal ios too close to the standard thermal throttling threshold. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Samples for the Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#BlofeldSamplesExtra ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
> Thanks, Adam and Hal. I will have a play. I need to decide which of my > flock to use, as some already sit in a fairly stable environment, and others > are doing real work which may be affected by running the CPU at 100%. > > OK, there's a non-critical one rather nearer to a CH radiator than I would > like, so I've started it there (no error messages after the edits you > suggested). I ran it as background and logged out. I guess it doesn't need > any privilege. > > https://www.satsignal.eu/mrtg/performance_raspi-12.php > > Thanks for drawing my attention to this. You can also keep the GPU busy. That'll work as well with the bonus that the main cpu stays mostly idle (iirc) for other tasks. https://vanheusden.com/ntpheat.cpp requires https://github.com/mn416/QPULib ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
The source code is here: https://github.com/ntpsec/ntpsec/blob/master/contrib/ntpheat It imports ntp.util. But from my rudimentary knowledge of Python I see that it only uses it to get version number. So I think removing lines 24-29 and 51-53 should make it work without ntpsec. Cheers, Adam = Thanks, Adam and Hal. I will have a play. I need to decide which of my flock to use, as some already sit in a fairly stable environment, and others are doing real work which may be affected by running the CPU at 100%. OK, there's a non-critical one rather nearer to a CH radiator than I would like, so I've started it there (no error messages after the edits you suggested). I ran it as background and logged out. I guess it doesn't need any privilege. https://www.satsignal.eu/mrtg/performance_raspi-12.php Thanks for drawing my attention to this. Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
On Mon, Mar 2, 2020 at 7:58 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > It's ~65°C on purpose. I'm using ntpheat ( > https://blog.ntpsec.org/2017/02/01/heat-it-up.html) to keep stable > temperature no matter what it does. It turns my raspberry into kind of OCXO > :) > Anyway, ntpheat runs there for months, so I guess it's not the culprit. > > Cheers, > Adam > > > Agreed, if it was running before then it's not the culprit this time. > > I didn't know about that program and I'd like to try it here. A neat > idea. > Is it available stand-alone - ready to run? I could compile it here given > the source, but not if it has dozens of dependencies on NTPsec, which I > don't use. > > Temperature is certainly the prime contributor to instability here (or > temperature variations produced by CPU load variations). > > Cheers, > David The source code is here: https://github.com/ntpsec/ntpsec/blob/master/contrib/ntpheat It imports ntp.util. But from my rudimentary knowledge of Python I see that it only uses it to get version number. So I think removing lines 24-29 and 51-53 should make it work without ntpsec. Cheers, Adam ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
> I didn't know about that program and I'd like to try it here. A neat idea. > Is it available stand-alone - ready to run? I could compile it here given > the source, but not if it has dozens of dependencies on NTPsec, which I > don't use. It's stand alone python code. There is nothing ntpsec specific in it. It does use a Linux hook to read the CPU temperature. If you can read the temperature on your system, that should be simple to fix. There are 2 versions. ntpheat uses the CPU to generate heat. ntpheatusb toggles a relay so you can use a light bulb under the CPU. -- These are my opinions. I hate spam. ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
It's ~65°C on purpose. I'm using ntpheat ( https://blog.ntpsec.org/2017/02/01/heat-it-up.html) to keep stable temperature no matter what it does. It turns my raspberry into kind of OCXO :) Anyway, ntpheat runs there for months, so I guess it's not the culprit. Cheers, Adam Agreed, if it was running before then it's not the culprit this time. I didn't know about that program and I'd like to try it here. A neat idea. Is it available stand-alone - ready to run? I could compile it here given the source, but not if it has dozens of dependencies on NTPsec, which I don't use. Temperature is certainly the prime contributor to instability here (or temperature variations produced by CPU load variations). Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
On Mon, Mar 2, 2020 at 5:23 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > Hi! > > For several weeks I'm seeing strange behavior of my Raspberry Pi based NTP > server with Uputronics GPS PPS expansion board (Ublox MAX-M8Q chip). > Several weeks ago the mean daily jitter was below 300 ns, offset didn't > exceed ±1 µs, provided no restart or configuration change was made. Now the > offset often wanders even below 5 µs, steady change, and then comes back. > You can see it at the screenshot from my Grafana server (attached). As you > can see, the number of satellites visible and TDOP value should not be the > cause of it. > > My current ntp.conf is as follows (I use ntpsec and gpsd): > > driftfile /var/lib/ntp/ntp.drift > leapfile /var/lib/ntp/leap-seconds.list > > statsdir /var/log/ntpstats/ > statistics loopstats peerstats > filegen loopstats file loopstats type day enable > filegen peerstats file peerstats type day enable > > restrict default limited kod nomodify nopeer noquery > restrict source nomodify noquery > restrict 127.0.0.1 > restrict 192.168.0.0 mask 255.255.0.0 > > tos mindist 0.002 > > refclock shm unit 1 minpoll 4 maxpoll 4 flag4 1 prefer refid PPS > refclock shm unit 0 minpoll 4 maxpoll 4 time1 0.057984 refid GPS > > #server nts.time.nl nts > #server nts.ntp.se:4443 nts > > server tempus1.gum.gov.pl prefer > server tempus2.gum.gov.pl > server ntp.task.gda.pl > server ntp.nask.pl > > server MY_GPSDO iburst > > Before that I thought it was because I used NTP pool, as some time ago > similar behavior was mentioned here on the list, but, as you can see, I do > not use it anymore and the same strange behavior remained. > > Any idea what could be the cause of this? Thanks in advance. > > Adam > > > What are you doing to that poor RPi to drive its CPU up to 66 C! Rather > hot! > > That's the first thing I would investigate if the CPU load is really so > low > (9%). Comparing, my oldest RPi server is a lowly RasPi 1B, and it runs at > 2% CPU, ~43 C CPU (averaged over a day). It lives in an unheated cupboard > on an outside wall. > > Cheers, > David > It's ~65°C on purpose. I'm using ntpheat ( https://blog.ntpsec.org/2017/02/01/heat-it-up.html) to keep stable temperature no matter what it does. It turns my raspberry into kind of OCXO :) Anyway, ntpheat runs there for months, so I guess it's not the culprit. Cheers, Adam ___ 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.
Re: [time-nuts] weird Raspberry PPS+GPS NTP server behaviour
Hi! For several weeks I'm seeing strange behavior of my Raspberry Pi based NTP server with Uputronics GPS PPS expansion board (Ublox MAX-M8Q chip). Several weeks ago the mean daily jitter was below 300 ns, offset didn't exceed ±1 µs, provided no restart or configuration change was made. Now the offset often wanders even below 5 µs, steady change, and then comes back. You can see it at the screenshot from my Grafana server (attached). As you can see, the number of satellites visible and TDOP value should not be the cause of it. My current ntp.conf is as follows (I use ntpsec and gpsd): driftfile /var/lib/ntp/ntp.drift leapfile /var/lib/ntp/leap-seconds.list statsdir /var/log/ntpstats/ statistics loopstats peerstats filegen loopstats file loopstats type day enable filegen peerstats file peerstats type day enable restrict default limited kod nomodify nopeer noquery restrict source nomodify noquery restrict 127.0.0.1 restrict 192.168.0.0 mask 255.255.0.0 tos mindist 0.002 refclock shm unit 1 minpoll 4 maxpoll 4 flag4 1 prefer refid PPS refclock shm unit 0 minpoll 4 maxpoll 4 time1 0.057984 refid GPS #server nts.time.nl nts #server nts.ntp.se:4443 nts server tempus1.gum.gov.pl prefer server tempus2.gum.gov.pl server ntp.task.gda.pl server ntp.nask.pl server MY_GPSDO iburst Before that I thought it was because I used NTP pool, as some time ago similar behavior was mentioned here on the list, but, as you can see, I do not use it anymore and the same strange behavior remained. Any idea what could be the cause of this? Thanks in advance. Adam What are you doing to that poor RPi to drive its CPU up to 66 C! Rather hot! That's the first thing I would investigate if the CPU load is really so low (9%). Comparing, my oldest RPi server is a lowly RasPi 1B, and it runs at 2% CPU, ~43 C CPU (averaged over a day). It lives in an unheated cupboard on an outside wall. Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ 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.
