NTPsec

Backup/Meinberg

Report generated: Wed Feb 4 00:33:00 2026 UTC
Start Time: Tue Feb 3 00:33:00 2026 UTC
End Time: Wed Feb 4 00:33:00 2026 UTC
Report Period: 1.0 days
Warning: plots clipped

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 -88.072 -82.501 -45.631 -1.159 66.600 134.466 151.506 112.231 216.967 31.712 0.131 µs 1.329 8.833
Local Clock Frequency Offset 4.724 4.735 4.787 4.959 5.266 5.331 5.334 0.479 0.596 0.115 4.981 ppm 1.002 5.149

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 0.574 0.660 0.764 1.248 4.583 9.072 13.645 3.819 8.412 1.616 1.845 µs 3.522 19.71

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 0.077 0.096 0.169 0.641 4.366 7.711 8.336 4.197 7.615 1.491 1.234 ppb 2.309 8.625

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 -88.072 -82.501 -45.631 -1.159 66.600 134.466 151.506 112.231 216.967 31.712 0.131 µs 1.329 8.833

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 4.724 4.735 4.787 4.959 5.266 5.331 5.334 0.479 0.596 0.115 4.981 ppm 1.002 5.149
Temp /dev/sda 41.000 41.000 41.000 42.000 43.000 44.000 44.000 2.000 3.000 0.511 42.053 °C
Temp /dev/sdb 52.000 52.000 52.000 53.000 60.000 60.000 60.000 8.000 8.000 2.911 54.634 °C
Temp /dev/sdc 53.000 53.000 53.000 53.000 54.000 56.000 56.000 1.000 3.000 0.496 53.169 °C
Temp /dev/sdd 59.000 59.000 59.000 60.000 69.000 69.000 69.000 10.000 10.000 3.689 62.049 °C
Temp /dev/sde 41.000 41.000 41.000 42.000 43.000 43.000 44.000 2.000 2.000 0.481 42.067 °C
Temp /dev/sdf 52.000 52.000 53.000 53.000 61.000 62.000 62.000 8.000 10.000 3.162 54.982 °C
Temp LM0 25.250 25.250 25.500 26.750 29.750 30.250 30.250 4.250 5.000 1.112 26.990 °C
Temp LM1 38.000 38.000 38.500 39.500 40.500 41.000 41.000 2.000 3.000 0.666 39.579 °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 41.000 41.000 41.000 42.000 43.000 44.000 44.000 2.000 3.000 0.511 42.053 °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 26.500 26.500 26.750 28.000 30.750 31.250 31.250 4.000 4.750 1.000 28.140 °C
Temp LM16 52.000 52.000 53.000 53.000 61.000 62.000 62.000 8.000 10.000 3.153 55.092 °C
Temp LM17 57.000 57.000 57.500 58.000 62.000 63.500 63.500 4.500 6.500 1.633 58.861 °C
Temp LM18 59.000 59.000 59.000 60.000 69.000 69.000 69.000 10.000 10.000 3.719 62.106 °C
Temp LM19 52.000 52.000 52.000 53.000 60.000 60.000 60.000 8.000 8.000 2.913 54.676 °C
Temp LM2 41.000 41.000 41.000 42.000 43.000 43.000 44.000 2.000 2.000 0.462 42.070 °C
Temp LM20 23.000 24.000 24.000 26.000 29.000 31.000 34.000 5.000 7.000 1.518 26.088 °C
Temp LM21 22.000 23.000 24.000 25.000 29.000 30.000 31.000 5.000 7.000 1.548 25.725 °C
Temp LM22 20.000 21.000 21.000 23.000 27.000 28.000 33.000 6.000 7.000 1.679 23.415 °C
Temp LM23 21.000 22.000 23.000 25.000 29.000 30.000 31.000 6.000 8.000 1.758 24.947 °C
Temp LM24 22.000 23.000 24.000 25.000 28.000 29.000 30.000 4.000 6.000 1.398 25.232 °C
Temp LM3 30.000 30.000 30.000 31.000 32.000 32.000 32.000 2.000 2.000 0.563 30.785 °C
Temp LM4 27.500 27.500 28.000 29.500 31.500 32.000 32.000 3.500 4.500 0.926 29.479 °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 29.000 29.000 29.000 29.000 29.000 29.000 29.000 0.000 0.000 0.000 29.000 °C
Temp LM7 57.000 57.000 57.000 58.000 62.000 63.000 63.000 5.000 6.000 1.633 58.641 °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 25.000 29.000 30.000 31.000 5.000 6.000 1.468 25.761 °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 57.000 57.000 57.500 58.000 62.000 63.500 64.000 4.500 6.500 1.642 58.852 °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) -2.068 -1.885 -1.421 0.249 2.183 2.647 2.908 3.604 4.532 1.167 0.549 ms -0.08481 1.951

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 -4.426 -4.189 -2.670 0.837 2.944 3.018 3.039 5.614 7.208 1.598 0.835 ms -1.044 4.458

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 -38.921 -27.612 -12.832 0.124 2.995 5.121 11.747 15.827 32.734 5.617 -1.154 ms -3.763 19.82

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 -1.335 -1.298 -0.969 0.219 0.727 0.867 0.989 1.695 2.165 0.432 0.149 ms -1.555 6.151

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) -88.073 -82.502 -45.632 -1.160 66.601 134.467 151.507 112.233 216.969 31.713 0.131 µs 1.329 8.833

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) 2.693 4.422 7.618 33.924 102.140 260.134 492.206 94.522 255.712 48.856 43.866 µs 5.419 43.13

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 4.451 7.281 9.412 26.522 165.550 380.802 460.103 156.138 373.521 65.281 48.748 µs 3.515 17.36

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 0.012 0.027 0.121 4.959 18.917 65.241 206.393 18.796 65.214 17.047 7.501 ms 9.096 99.41

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 20.329 38.941 67.006 116.867 175.584 199.601 275.668 108.578 160.660 34.175 117.961 µs 0.2752 3.761

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) 0.176 0.515 0.891 3.307 14.032 41.824 77.020 13.141 41.309 7.190 5.096 µs 5.482 42.71

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 4.724 4.735 4.787 4.959 5.266 5.331 5.334 0.479 0.596 0.115 4.981 ppm 1.002 5.149
Local Clock Time Offset -88.072 -82.501 -45.631 -1.159 66.600 134.466 151.506 112.231 216.967 31.712 0.131 µs 1.329 8.833
Local RMS Frequency Jitter 0.077 0.096 0.169 0.641 4.366 7.711 8.336 4.197 7.615 1.491 1.234 ppb 2.309 8.625
Local RMS Time Jitter 0.574 0.660 0.764 1.248 4.583 9.072 13.645 3.819 8.412 1.616 1.845 µs 3.522 19.71
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 2.693 4.422 7.618 33.924 102.140 260.134 492.206 94.522 255.712 48.856 43.866 µs 5.419 43.13
Server Jitter 204.17.205.1 4.451 7.281 9.412 26.522 165.550 380.802 460.103 156.138 373.521 65.281 48.748 µs 3.515 17.36
Server Jitter 204.17.205.24 0.012 0.027 0.121 4.959 18.917 65.241 206.393 18.796 65.214 17.047 7.501 ms 9.096 99.41
Server Jitter 204.17.205.27 20.329 38.941 67.006 116.867 175.584 199.601 275.668 108.578 160.660 34.175 117.961 µs 0.2752 3.761
Server Jitter SHM(0) 0.176 0.515 0.891 3.307 14.032 41.824 77.020 13.141 41.309 7.190 5.096 µs 5.482 42.71
Server Offset 2001:470:e815::8 (spidey.rellim.com) -2.068 -1.885 -1.421 0.249 2.183 2.647 2.908 3.604 4.532 1.167 0.549 ms -0.08481 1.951
Server Offset 204.17.205.1 -4.426 -4.189 -2.670 0.837 2.944 3.018 3.039 5.614 7.208 1.598 0.835 ms -1.044 4.458
Server Offset 204.17.205.24 -38.921 -27.612 -12.832 0.124 2.995 5.121 11.747 15.827 32.734 5.617 -1.154 ms -3.763 19.82
Server Offset 204.17.205.27 -1.335 -1.298 -0.969 0.219 0.727 0.867 0.989 1.695 2.165 0.432 0.149 ms -1.555 6.151
Server Offset SHM(0) -88.073 -82.502 -45.632 -1.160 66.601 134.467 151.507 112.233 216.969 31.713 0.131 µs 1.329 8.833
Temp /dev/sda 41.000 41.000 41.000 42.000 43.000 44.000 44.000 2.000 3.000 0.511 42.053 °C
Temp /dev/sdb 52.000 52.000 52.000 53.000 60.000 60.000 60.000 8.000 8.000 2.911 54.634 °C
Temp /dev/sdc 53.000 53.000 53.000 53.000 54.000 56.000 56.000 1.000 3.000 0.496 53.169 °C
Temp /dev/sdd 59.000 59.000 59.000 60.000 69.000 69.000 69.000 10.000 10.000 3.689 62.049 °C
Temp /dev/sde 41.000 41.000 41.000 42.000 43.000 43.000 44.000 2.000 2.000 0.481 42.067 °C
Temp /dev/sdf 52.000 52.000 53.000 53.000 61.000 62.000 62.000 8.000 10.000 3.162 54.982 °C
Temp LM0 25.250 25.250 25.500 26.750 29.750 30.250 30.250 4.250 5.000 1.112 26.990 °C
Temp LM1 38.000 38.000 38.500 39.500 40.500 41.000 41.000 2.000 3.000 0.666 39.579 °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 41.000 41.000 41.000 42.000 43.000 44.000 44.000 2.000 3.000 0.511 42.053 °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 26.500 26.500 26.750 28.000 30.750 31.250 31.250 4.000 4.750 1.000 28.140 °C
Temp LM16 52.000 52.000 53.000 53.000 61.000 62.000 62.000 8.000 10.000 3.153 55.092 °C
Temp LM17 57.000 57.000 57.500 58.000 62.000 63.500 63.500 4.500 6.500 1.633 58.861 °C
Temp LM18 59.000 59.000 59.000 60.000 69.000 69.000 69.000 10.000 10.000 3.719 62.106 °C
Temp LM19 52.000 52.000 52.000 53.000 60.000 60.000 60.000 8.000 8.000 2.913 54.676 °C
Temp LM2 41.000 41.000 41.000 42.000 43.000 43.000 44.000 2.000 2.000 0.462 42.070 °C
Temp LM20 23.000 24.000 24.000 26.000 29.000 31.000 34.000 5.000 7.000 1.518 26.088 °C
Temp LM21 22.000 23.000 24.000 25.000 29.000 30.000 31.000 5.000 7.000 1.548 25.725 °C
Temp LM22 20.000 21.000 21.000 23.000 27.000 28.000 33.000 6.000 7.000 1.679 23.415 °C
Temp LM23 21.000 22.000 23.000 25.000 29.000 30.000 31.000 6.000 8.000 1.758 24.947 °C
Temp LM24 22.000 23.000 24.000 25.000 28.000 29.000 30.000 4.000 6.000 1.398 25.232 °C
Temp LM3 30.000 30.000 30.000 31.000 32.000 32.000 32.000 2.000 2.000 0.563 30.785 °C
Temp LM4 27.500 27.500 28.000 29.500 31.500 32.000 32.000 3.500 4.500 0.926 29.479 °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 29.000 29.000 29.000 29.000 29.000 29.000 29.000 0.000 0.000 0.000 29.000 °C
Temp LM7 57.000 57.000 57.000 58.000 62.000 63.000 63.000 5.000 6.000 1.633 58.641 °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 25.000 29.000 30.000 31.000 5.000 6.000 1.468 25.761 °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 57.000 57.000 57.500 58.000 62.000 63.500 64.000 4.500 6.500 1.642 58.852 °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.



This page autogenerated by ntpviz, part of the NTPsec project
html 5    Valid CSS!