NTPsec

Backup/Meinberg

Report generated: Wed Nov 4 16:43:01 2026 UTC
Start Time: Wed Oct 28 16:43:00 2026 UTC
End Time: Wed Nov 4 16:43:00 2026 UTC
Report Period: 7.0 days

Daily stats   Weekly stats  

Local Clock Time/Frequency Offsets

local offset plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Time Offset -177.184 -80.833 -49.684 -3.166 52.382 97.718 1,730.160 102.066 178.551 42.382 -0.425 µs 15.31 555.6
Local Clock Frequency Offset 3.944 3.980 4.052 4.396 6.103 6.374 6.745 2.051 2.394 0.815 5.003 ppm 0.2219 1.272

The time and frequency offsets between the ntpd calculated time and the local system clock. Showing frequency offset (red, in parts per million, scale on right) and the time offset (blue, in μs, scale on left). Quick changes in time offset will lead to larger frequency offsets.

These are fields 3 (time) and 4 (frequency) from the loopstats log file.



Local RMS Time Jitter

local jitter plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Time Jitter 0.416 0.535 0.650 2.285 62.255 79.557 643.621 61.605 79.022 33.679 22.300 µs 7.528 112.2

The RMS Jitter of the local clock offset. In other words, how fast the local clock offset is changing.

Lower is better. An ideal system would be a horizontal line at 0μs.

RMS jitter is field 5 in the loopstats log file.



Local RMS Frequency Jitter

local stability plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Frequency Jitter 0.000 0.152 0.212 2.070 32.392 50.377 142.899 32.180 50.225 13.425 11.152 ppb 2.031 13.5

The RMS Frequency Jitter (aka wander) of the local clock's frequency. In other words, how fast the local clock changes frequency.

Lower is better. An ideal clock would be a horizontal line at 0ppm.

RMS Frequency Jitter is field 6 in the loopstats log file.



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -177.184 -80.833 -49.684 -3.166 52.382 97.718 1,730.160 102.066 178.551 42.382 -0.425 µs 15.31 555.6

The clock offsets of the local clock as a histogram.

The Local Clock Offset is field 3 from the loopstats log file.



Local Temperatures

local temps plot

Local temperatures. These will be site-specific depending upon what temperature sensors you collect data from. Temperature changes affect the local clock crystal frequency and stability. The math of how temperature changes frequency is complex, and also depends on crystal aging. So there is no easy way to correct for it in software. This is the single most important component of frequency drift.

The Local Temperatures are from field 3 from the tempstats log file.



Local Frequency/Temp

local freq temps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 3.944 3.980 4.052 4.396 6.103 6.374 6.745 2.051 2.394 0.815 5.003 ppm 0.2219 1.272
Temp /dev/sda 60.000 60.000 61.000 62.000 64.000 65.000 71.000 3.000 5.000 1.047 62.473 °C
Temp /dev/sdb 43.000 43.000 44.000 45.000 49.000 50.000 51.000 5.000 7.000 1.572 45.294 °C
Temp /dev/sdc 53.000 53.000 53.000 56.000 58.000 60.000 63.000 5.000 7.000 1.497 55.262 °C
Temp /dev/sdd 67.000 67.000 67.000 69.000 72.000 74.000 79.000 5.000 7.000 1.484 69.072 °C
Temp /dev/sde 46.000 46.000 46.000 48.000 53.000 54.000 54.000 7.000 8.000 1.713 48.283 °C
Temp /dev/sdf 44.000 44.000 45.000 46.000 51.000 52.000 52.000 6.000 8.000 1.701 46.337 °C
Temp LM0 25.000 25.250 25.500 27.000 29.750 35.750 39.000 4.250 10.500 1.567 27.148 °C
Temp LM1 36.500 37.500 38.000 39.000 40.000 41.500 42.500 2.000 4.000 0.727 39.024 °C
Temp LM10 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM11 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM12 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM13 27.800 27.800 27.800 27.800 27.800 27.800 27.800 0.000 0.000 0.000 27.800 °C
Temp LM14 29.800 29.800 29.800 29.800 29.800 29.800 29.800 0.000 0.000 0.000 29.800 °C
Temp LM15 26.250 26.500 26.750 28.250 30.750 33.000 35.000 4.000 6.500 1.180 28.338 °C
Temp LM16 44.000 44.000 45.000 46.000 51.000 52.000 52.000 6.000 8.000 1.714 46.340 °C
Temp LM17 56.500 56.500 57.000 58.500 61.500 62.500 64.000 4.500 6.000 1.182 58.427 °C
Temp LM18 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM19 43.000 43.000 44.000 45.000 49.000 50.000 51.000 5.000 7.000 1.596 45.283 °C
Temp LM2 46.000 46.000 46.000 48.000 53.000 54.000 54.000 7.000 8.000 1.725 48.288 °C
Temp LM20 23.000 24.000 24.000 26.000 30.000 57.000 72.000 6.000 33.000 4.447 26.684 °C
Temp LM21 22.000 23.000 24.000 26.000 30.000 48.000 72.000 6.000 25.000 3.902 26.472 °C
Temp LM22 21.000 22.000 22.000 24.000 28.000 51.000 66.000 6.000 29.000 4.098 24.764 °C
Temp LM23 21.000 22.000 23.000 25.000 29.000 52.000 68.000 6.000 30.000 4.192 25.560 °C
Temp LM24 22.000 22.000 23.000 25.000 28.000 49.000 63.000 5.000 27.000 3.729 25.236 °C
Temp LM3 29.000 29.000 30.000 31.000 32.000 35.000 37.000 2.000 6.000 0.950 31.099 °C
Temp LM4 27.500 27.500 28.000 29.500 31.500 32.000 33.500 3.500 4.500 1.061 29.714 °C
Temp LM5 24.000 24.000 24.000 24.000 24.000 24.000 24.000 0.000 0.000 0.000 24.000 °C
Temp LM6 23.000 23.500 24.000 25.500 29.500 57.000 69.500 5.500 33.500 4.404 26.334 °C
Temp LM7 56.000 56.000 57.000 58.000 61.000 62.000 64.000 4.000 6.000 1.241 58.212 °C
Temp LM8 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp ZONE0 23.000 24.000 24.000 26.000 30.000 57.000 72.000 6.000 33.000 4.476 26.562 °C
Temp ZONE1 27.800 27.800 27.800 27.800 27.800 27.800 27.800 0.000 0.000 0.000 27.800 °C
Temp ZONE2 56.500 56.500 57.000 58.500 61.500 62.500 64.500 4.500 6.000 1.184 58.427 °C
Temp ZONE3 29.800 29.800 29.800 29.800 29.800 29.800 29.800 0.000 0.000 0.000 29.800 °C

The frequency offsets and temperatures. Showing frequency offset (red, in parts per million, scale on right) and the temperatures.

These are field 4 (frequency) from the loopstats log file, and field 3 from the tempstats log file.



Server Offsets

peer offsets plot

The offset of all refclocks and servers. This can be useful to see if offset changes are happening in a single clock or all clocks together.

Clock Offset is field 5 in the peerstats log file.



Server Offset 2001:470:e815::8 (spidey.rellim.com)

peer offset 2001:470:e815::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1,200.319 -577.800 -303.212 41.581 283.586 559.009 1,673.490 586.798 1,136.809 213.726 18.613 µs -0.4153 9.262

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.1

peer offset 204.17.205.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.1 -4.659 -3.713 -0.660 0.035 0.747 2.844 3.550 1.407 6.557 0.730 0.012 ms -1.471 19.03

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.24

peer offset 204.17.205.24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.24 -296.370 -130.991 -82.972 14.299 89.074 181.250 2,040.946 172.046 312.241 85.822 14.544 µs 10.72 213.5

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.27

peer offset 204.17.205.27 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.27 -698.682 -224.959 -77.985 29.183 118.340 278.551 1,693.922 196.325 503.510 94.995 28.700 µs 4.301 88.83

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(0)

peer offset SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(0) -66.597 -51.405 -19.622 -3.447 37.068 70.419 247.494 56.690 121.824 23.244 -0.663 µs 3.972 34.3

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Jitters

peer jitters plot

The RMS Jitter of all refclocks and servers. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:470:e815::8 (spidey.rellim.com)

peer jitter 2001:470:e815::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 0.000 2.927 5.148 22.255 76.973 107.609 1,242.687 71.825 104.682 35.994 30.310 µs 17.71 549.3

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.1

peer jitter 204.17.205.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.1 0.000 5.733 9.853 23.513 67.393 175.258 1,211.574 57.540 169.525 36.065 30.708 µs 13.07 333

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.24

peer jitter 204.17.205.24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.24 0.000 3.403 5.746 24.367 70.463 102.442 1,424.123 64.717 99.039 54.182 30.866 µs 19.54 451.7

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.27

peer jitter 204.17.205.27 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.27 0.000 6.155 11.411 80.798 156.451 200.201 1,280.175 145.040 194.046 51.866 80.249 µs 3.879 80.14

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(0)

peer jitter SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(0) 0.184 0.416 0.648 2.322 10.064 32.669 94.419 9.416 32.253 6.469 3.786 µs 7.776 82.4

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 3.944 3.980 4.052 4.396 6.103 6.374 6.745 2.051 2.394 0.815 5.003 ppm 0.2219 1.272
Local Clock Time Offset -177.184 -80.833 -49.684 -3.166 52.382 97.718 1,730.160 102.066 178.551 42.382 -0.425 µs 15.31 555.6
Local RMS Frequency Jitter 0.000 0.152 0.212 2.070 32.392 50.377 142.899 32.180 50.225 13.425 11.152 ppb 2.031 13.5
Local RMS Time Jitter 0.416 0.535 0.650 2.285 62.255 79.557 643.621 61.605 79.022 33.679 22.300 µs 7.528 112.2
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 0.000 2.927 5.148 22.255 76.973 107.609 1,242.687 71.825 104.682 35.994 30.310 µs 17.71 549.3
Server Jitter 204.17.205.1 0.000 5.733 9.853 23.513 67.393 175.258 1,211.574 57.540 169.525 36.065 30.708 µs 13.07 333
Server Jitter 204.17.205.24 0.000 3.403 5.746 24.367 70.463 102.442 1,424.123 64.717 99.039 54.182 30.866 µs 19.54 451.7
Server Jitter 204.17.205.27 0.000 6.155 11.411 80.798 156.451 200.201 1,280.175 145.040 194.046 51.866 80.249 µs 3.879 80.14
Server Jitter SHM(0) 0.184 0.416 0.648 2.322 10.064 32.669 94.419 9.416 32.253 6.469 3.786 µs 7.776 82.4
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1,200.319 -577.800 -303.212 41.581 283.586 559.009 1,673.490 586.798 1,136.809 213.726 18.613 µs -0.4153 9.262
Server Offset 204.17.205.1 -4.659 -3.713 -0.660 0.035 0.747 2.844 3.550 1.407 6.557 0.730 0.012 ms -1.471 19.03
Server Offset 204.17.205.24 -296.370 -130.991 -82.972 14.299 89.074 181.250 2,040.946 172.046 312.241 85.822 14.544 µs 10.72 213.5
Server Offset 204.17.205.27 -698.682 -224.959 -77.985 29.183 118.340 278.551 1,693.922 196.325 503.510 94.995 28.700 µs 4.301 88.83
Server Offset SHM(0) -66.597 -51.405 -19.622 -3.447 37.068 70.419 247.494 56.690 121.824 23.244 -0.663 µs 3.972 34.3
Temp /dev/sda 60.000 60.000 61.000 62.000 64.000 65.000 71.000 3.000 5.000 1.047 62.473 °C
Temp /dev/sdb 43.000 43.000 44.000 45.000 49.000 50.000 51.000 5.000 7.000 1.572 45.294 °C
Temp /dev/sdc 53.000 53.000 53.000 56.000 58.000 60.000 63.000 5.000 7.000 1.497 55.262 °C
Temp /dev/sdd 67.000 67.000 67.000 69.000 72.000 74.000 79.000 5.000 7.000 1.484 69.072 °C
Temp /dev/sde 46.000 46.000 46.000 48.000 53.000 54.000 54.000 7.000 8.000 1.713 48.283 °C
Temp /dev/sdf 44.000 44.000 45.000 46.000 51.000 52.000 52.000 6.000 8.000 1.701 46.337 °C
Temp LM0 25.000 25.250 25.500 27.000 29.750 35.750 39.000 4.250 10.500 1.567 27.148 °C
Temp LM1 36.500 37.500 38.000 39.000 40.000 41.500 42.500 2.000 4.000 0.727 39.024 °C
Temp LM10 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM11 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM12 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM13 27.800 27.800 27.800 27.800 27.800 27.800 27.800 0.000 0.000 0.000 27.800 °C
Temp LM14 29.800 29.800 29.800 29.800 29.800 29.800 29.800 0.000 0.000 0.000 29.800 °C
Temp LM15 26.250 26.500 26.750 28.250 30.750 33.000 35.000 4.000 6.500 1.180 28.338 °C
Temp LM16 44.000 44.000 45.000 46.000 51.000 52.000 52.000 6.000 8.000 1.714 46.340 °C
Temp LM17 56.500 56.500 57.000 58.500 61.500 62.500 64.000 4.500 6.000 1.182 58.427 °C
Temp LM18 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM19 43.000 43.000 44.000 45.000 49.000 50.000 51.000 5.000 7.000 1.596 45.283 °C
Temp LM2 46.000 46.000 46.000 48.000 53.000 54.000 54.000 7.000 8.000 1.725 48.288 °C
Temp LM20 23.000 24.000 24.000 26.000 30.000 57.000 72.000 6.000 33.000 4.447 26.684 °C
Temp LM21 22.000 23.000 24.000 26.000 30.000 48.000 72.000 6.000 25.000 3.902 26.472 °C
Temp LM22 21.000 22.000 22.000 24.000 28.000 51.000 66.000 6.000 29.000 4.098 24.764 °C
Temp LM23 21.000 22.000 23.000 25.000 29.000 52.000 68.000 6.000 30.000 4.192 25.560 °C
Temp LM24 22.000 22.000 23.000 25.000 28.000 49.000 63.000 5.000 27.000 3.729 25.236 °C
Temp LM3 29.000 29.000 30.000 31.000 32.000 35.000 37.000 2.000 6.000 0.950 31.099 °C
Temp LM4 27.500 27.500 28.000 29.500 31.500 32.000 33.500 3.500 4.500 1.061 29.714 °C
Temp LM5 24.000 24.000 24.000 24.000 24.000 24.000 24.000 0.000 0.000 0.000 24.000 °C
Temp LM6 23.000 23.500 24.000 25.500 29.500 57.000 69.500 5.500 33.500 4.404 26.334 °C
Temp LM7 56.000 56.000 57.000 58.000 61.000 62.000 64.000 4.000 6.000 1.241 58.212 °C
Temp LM8 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp ZONE0 23.000 24.000 24.000 26.000 30.000 57.000 72.000 6.000 33.000 4.476 26.562 °C
Temp ZONE1 27.800 27.800 27.800 27.800 27.800 27.800 27.800 0.000 0.000 0.000 27.800 °C
Temp ZONE2 56.500 56.500 57.000 58.500 61.500 62.500 64.500 4.500 6.000 1.184 58.427 °C
Temp ZONE3 29.800 29.800 29.800 29.800 29.800 29.800 29.800 0.000 0.000 0.000 29.800 °C
Summary as CSV file


This server:

CPU: Quad core Intel Xeon E3-1241 v3
Kernel: config.gz
Motherboard: Supermicro X10SAE
OS: Gentoo stable
GPS; Meinberg GPS180PEX
GPS/PPS server: gpsd
NTP server: NTPsec
ntp.conf: current
ntp.log: current

Notes:

Notes:
03:20Z 20 Dec 2018 Change poll from 8s to 4s.  4s seems best.
01:30Z 20 Dec 2018 Change poll from 2s to 8s.
23:00Z 20 Dec 2018 Change poll from 4s to 2s.
22:00Z 20 Dec 2018 Change poll from 64s to 4s.
21:40  19 Dec 2018 -- just started

Poll:
64s   SHM(0) offset StdDev 34.5 us, jitter 5.3 us
8s    8s better jitter than 4s, but worse offset than 4s
4s    SHM(0) offset mean 0 ns StdDev 481 ns, jitter 449 ns StdDev 250 ns
      better than 2s, almost unstable
2s    




Glossary:

frequency offset:
The difference between the ntpd calculated frequency and the local system clock frequency (usually in parts per million, ppm)
jitter, dispersion:
The short term change in a value. NTP measures Local Time Jitter, Refclock Jitter, and Server Jitter in seconds. Local Frequency Jitter is in ppm or ppb.
ms, millisecond:
One thousandth of a second = 0.001 seconds, 1e-3 seconds
mu, mean:
The arithmetic mean: the sum of all the values divided by the number of values. The formula for mu is: "mu = (∑xi) / N". Where xi denotes the data points and N is the number of data points.
ns, nanosecond:
One billionth of a second, also one thousandth of a microsecond, 0.000000001 seconds and 1e-9 seconds.
percentile:
The value below which a given percentage of values fall.
ppb, parts per billion:
Ratio between two values. These following are all the same: 1 ppb, one in one billion, 1/1,000,000,000, 0.000,000,001, 1e-9 and 0.000,000,1%
ppm, parts per million:
Ratio between two values. These following are all the same: 1 ppm, one in one million, 1/1,000,000, 0.000,001, and 0.000,1%
‰, parts per thousand:
Ratio between two values. These following are all the same: 1 ‰. one in one thousand, 1/1,000, 0.001, and 0.1%
refclock:
Reference clock, a local GPS module or other local source of time.
remote clock:
Any clock reached over the network, LAN or WAN. Also called a peer or server.
time offset:
The difference between the ntpd calculated time and the local system clock's time. Also called phase offset.
σ, sigma:
Sigma denotes the standard deviation (SD) and is centered on the arithmetic mean of the data set. The SD is simply the square root of the variance of the data set. Two sigma is simply twice the standard deviation. Three sigma is three times sigma. Smaller is better.
The formula for sigma is: "σ = √[ ∑(xi-mu)^2 / N ]". Where xi denotes the data points and N is the number of data points.
Skewness, Skew:
The skewness of a random variable X is the third standardized moment and is a dimension-less ratio. ntpviz uses the FIsher-Pearson moment of skewness. There are other different ways to calculate Skewness Wikipedia describes Skewness best: "The qualitative interpretation of the skew is complicated and unintuitive."
A normal distribution has a skewness of zero.
Kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses standard Kurtosis. There are other different ways to calculate Kurtosis.
A normal distribution has a Kurtosis of three. NIST describes a kurtosis over three as "heavy tailed" and one under three as "light tailed".
upstream clock:
Any server or reference clock used as a source of time.
µs, us, microsecond:
One millionth of a second, also one thousandth of a millisecond, 0.000,001 seconds, and 1e-6 seconds.



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