ntpMerlin ntpMerlin v3.x

ottofreud

Occasional Visitor
Good test. Won't be able to do that immediately, but will do so in the next day or so for 12 - 24 hours and see what the results are. I'll report back when I get some data.
Some data after 12 hours of no fan. Temp: avg 62 C (~ 37 C with fan), Offset avg 2.9 ms (0.09 ms with fan), drift avg 8.46 ppm (4.4 ppm with fan) From that very limited data sample, it looks like NTP offset and drift get worse with CPU temp. Again, very little data and lots of possible unknown causation. Also, the cyclical pattern in the drift graph was still there with the absolute values of the max and min for each cycle being greater than that of the system with a fan.
 
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Maverickcdn

Senior Member
from me? no :D
but if @Maverickcdn wants to add historical logging and charts, I'm happy to lend a hand if required
I've been holding my face against the monitor with a JackYaz github page open but osmosis isnt working ;)

Ill learn the addons API here at some point and will look at doing something as I see theres plenty of stats lovers, don't hold your breath for anytime in the near future
 

heysoundude

Part of the Furniture
Some data after 12 hours of no fan. Temp: avg 62 C (~ 37 C with fan), Offset avg 2.9 ms (0.09 ms with fan), drift avg 8.46 ppm (4.4 ppm with fan) From that very limited data sample, it looks like NTP offset and drift get worse with CPU temp. Again, very little data and lots of possible unknown causation. Also, the cyclical pattern in the drift graph was still there with the absolute values of the max and min for each cycle being greater than that of the system with a fan.
I don't know about you, but I tend to slow down and get sloppy/relaxed too when I feel warmer. A bit of shade, a cool drink, a nice breeze...;-)

what would be great for charting is if a bunch of the data collected by the scripts could be correlated on one screen/graph that's user-configurable. In the GUI/tabs would be nice, but taking the raw data out to a spreadsheet for graphing shouldn't too much of an issue...hmmm...
 

Wade Coxon

Senior Member
Some data after 12 hours of no fan. Temp: avg 62 C (~ 37 C with fan), Offset avg 2.9 ms (0.09 ms with fan), drift avg 8.46 ppm (4.4 ppm with fan) From that very limited data sample, it looks like NTP offset and drift get worse with CPU temp. Again, very little data and lots of possible unknown causation. Also, the cyclical pattern in the drift graph was still there with the absolute values of the max and min for each cycle being greater than that of the system with a fan.
I think this is another case of the clock drift not being associated with the CPU temperature, but rather the board temperature. The problem is that the board temperature is not directly measurable.

From the drift graph that was posted earlier, a +/- 2ppm drift in response to ambient temperatures changing seems about right.

From the material I have read, your average crystal oscillator will drift about 1ppm per degree Celsius.
My old PCs running NTPD used to run at an average drift of about 20-30ppm, which would certainly correspond with that rule of thumb.

So I reckon that even with the ambient temperature changing by about 10 degrees between morning and night, this probably only translates into a change of board temperature of a couple of degrees, which leads to a corresponding fluctuation in the drift.

Adding the fan to the router may drop the CPU temperature by many tens of degrees, but likely is not dropping the board temperature a whole lot, as the board will already be far closer to ambient, than the CPU is.
 

Jack Yaz

Part of the Furniture
Screenshot_20210312-095912_Chrome.png

#nerdhumour
 

ottofreud

Occasional Visitor
I think this is another case of the clock drift not being associated with the CPU temperature, but rather the board temperature. The problem is that the board temperature is not directly measurable.

From the drift graph that was posted earlier, a +/- 2ppm drift in response to ambient temperatures changing seems about right.

From the material I have read, your average crystal oscillator will drift about 1ppm per degree Celsius.
My old PCs running NTPD used to run at an average drift of about 20-30ppm, which would certainly correspond with that rule of thumb.

So I reckon that even with the ambient temperature changing by about 10 degrees between morning and night, this probably only translates into a change of board temperature of a couple of degrees, which leads to a corresponding fluctuation in the drift.

Adding the fan to the router may drop the CPU temperature by many tens of degrees, but likely is not dropping the board temperature a whole lot, as the board will already be far closer to ambient, than the CPU is.
good points. Might be a fun project to use and old router and add a thermal sensor on, or close to, the timing circuit and then repeat the experiment. Sounds like a fun summer project for the kids! :)
 

JGrana

Very Senior Member
More like #70OldiesHumor...
 

Frejoh4666

Occasional Visitor
So after installing this I noticed that my google nest mini was connecting to www.google.com ~21000 times and time.google.com ~1400 times the last week.

I'm using chrony and redirecting all NTP calls. Should/can I whitelist the nest, or is there an other solution to stop the nest freakingout about it?
 

archiel

Senior Member
ITS SUMMERTIME!!
or at least that is what ntpmerlin has decided!
Code:
##          _           __  __              _  _          ##
##         | |         |  \/  |            | |(_)         ##
##   _ __  | |_  _ __  | \  / |  ___  _ __ | | _  _ __    ##
##  | '_ \ | __|| '_ \ | |\/| | / _ \| '__|| || || '_ \   ##
##  | | | || |_ | |_) || |  | ||  __/| |   | || || | | |  ##
##  |_| |_| \__|| .__/ |_|  |_| \___||_|   |_||_||_| |_|  ##
##              | |                                       ##
##              |_|                                       ##
##                                                        ##
##                   v3.2.2 on RT-AX88U                   ##
##                                                        ##
##        https://github.com/jackyaz/ntpMerlin            ##
##                                                        ##
##             Time server in use: chronyd                ##
##  Config location: /opt/share/ntpmerlin.d/chrony.conf   ##
##                                                        ##
##                DST is currently Active                 ##
##                                                        ##
##     DST starts on Month 3 Week 5 Weekday 0 Hour 1      ##
##     DST ends on Month 10 Week 5 Weekday 0 Hour 2       ##
##                                                        ##
############################################################

My Timezone setting is GMT (Dublin, Edinburgh, Lisbon, London)

Same problem with both ntp and chrony (and rebooting doesn't help)

Any suggestion how I can persuade ntpmerlin is is still just Month 3 Week 3 Weekday 1?

for now I have set Option 2. Toggle redirect of all NTP traffic to ntpMerlin to disabled, so as not to confuse the rest of the network.
 

Jack Yaz

Part of the Furniture
ITS SUMMERTIME!!
or at least that is what ntpmerlin has decided!
Code:
##          _           __  __              _  _          ##
##         | |         |  \/  |            | |(_)         ##
##   _ __  | |_  _ __  | \  / |  ___  _ __ | | _  _ __    ##
##  | '_ \ | __|| '_ \ | |\/| | / _ \| '__|| || || '_ \   ##
##  | | | || |_ | |_) || |  | ||  __/| |   | || || | | |  ##
##  |_| |_| \__|| .__/ |_|  |_| \___||_|   |_||_||_| |_|  ##
##              | |                                       ##
##              |_|                                       ##
##                                                        ##
##                   v3.2.2 on RT-AX88U                   ##
##                                                        ##
##        https://github.com/jackyaz/ntpMerlin            ##
##                                                        ##
##             Time server in use: chronyd                ##
##  Config location: /opt/share/ntpmerlin.d/chrony.conf   ##
##                                                        ##
##                DST is currently Active                 ##
##                                                        ##
##     DST starts on Month 3 Week 5 Weekday 0 Hour 1      ##
##     DST ends on Month 10 Week 5 Weekday 0 Hour 2       ##
##                                                        ##
############################################################

Same problem with both ntp and chrony (and rebooting doesn't help)

Any suggestion how I can persuade ntpmerlin is is still just Month 3 Week 3 Weekday 1?

for now I have set Option 2. Toggle redirect of all NTP traffic to ntpMerlin to disabled, so as not to confuse the rest of the network.
sigh. NTP does not convey timezone data. http://www.snbforums.com/threads/that-time-of-year-again-dst.71137/post-672985
this is a bug in the firmware that is erroneously enabling DST for some timezones.
 

maghuro

Very Senior Member
Screenshot_20210315-173022088.png


What is curious is that DST is on (which is wrong), but the time in router is correct, as you can see comparing to my smartphone clock
 

Vexira

Part of the Furniture
So after installing this I noticed that my google nest mini was connecting to www.google.com ~21000 times and time.google.com ~1400 times the last week.

I'm using chrony and redirecting all NTP calls. Should/can I whitelist the nest, or is there an other solution to stop the nest freakingout about it?
May I ask what you are using to monitor this behaviour?
 

cplay

Senior Member
I stated previoiusly it may be a co-incidence and am a maths and science person. I don't go off whims, but look for proof to underline things I find.

One thing is for certain, I've gone from +/- 1.5ms to less than +/- 0.1ms... I've found better performance outside of things that have been mentioned, which may be entirely a co-incidence. I'm happy to be presented with facts and evidence to support or otherwise, over hysterical responses.
Are those screenshots comparing ntpd vs chrony?

also do I need to enable ntp server in administration time settings for chrony to work in ntp merlin?
 

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