NTPsec

Backup/Meinberg

Report generated: Wed May 6 10:33:00 2026 UTC
Start Time: Tue May 5 10:33:00 2026 UTC
End Time: Wed May 6 10:33:00 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 -97.827 -91.503 -36.968 -0.852 29.288 112.463 135.840 66.256 203.966 26.683 -0.160 µs 0.6378 10.55
Local Clock Frequency Offset 11.792 11.793 11.807 12.095 12.323 12.333 12.334 0.516 0.540 0.153 12.072 ppm -0.2195 2.149

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 0.447 0.549 0.633 0.958 3.540 7.830 12.492 2.907 7.281 1.392 1.470 µs 3.909 22.78

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 0.128 0.155 0.220 0.712 4.278 6.528 7.322 4.058 6.373 1.222 1.077 ppb 2.915 11.72

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 -97.827 -91.503 -36.968 -0.852 29.288 112.463 135.840 66.256 203.966 26.683 -0.160 µs 0.6378 10.55

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 11.792 11.793 11.807 12.095 12.323 12.333 12.334 0.516 0.540 0.153 12.072 ppm -0.2195 2.149
Temp /dev/sda 44.000 44.000 45.000 46.000 47.000 49.000 49.000 2.000 5.000 0.794 45.687 °C
Temp /dev/sdb 55.000 55.000 55.000 56.000 65.000 65.000 65.000 10.000 10.000 3.268 57.989 °C
Temp /dev/sdc 56.000 56.000 56.000 56.000 58.000 61.000 61.000 2.000 5.000 1.034 56.658 °C
Temp /dev/sdd 62.000 62.000 62.000 63.000 73.000 73.000 73.000 11.000 11.000 3.847 65.229 °C
Temp /dev/sde 44.000 44.000 44.000 46.000 46.000 47.000 47.000 2.000 3.000 0.631 45.496 °C
Temp /dev/sdf 56.000 56.000 56.000 57.000 65.000 65.000 65.000 9.000 9.000 3.289 58.535 °C
Temp LM0 28.750 28.750 29.000 30.250 32.250 33.250 34.000 3.250 4.500 1.055 30.446 °C
Temp LM1 40.000 40.000 40.000 41.500 42.000 42.500 42.500 2.000 2.500 0.606 41.303 °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 44.000 44.000 45.000 46.000 47.000 49.000 49.000 2.000 5.000 0.798 45.690 °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 30.000 30.000 30.250 31.500 33.000 33.750 34.250 2.750 3.750 0.867 31.563 °C
Temp LM16 56.000 56.000 56.000 57.000 65.000 65.000 65.000 9.000 9.000 3.247 58.651 °C
Temp LM17 60.000 60.000 60.000 61.500 66.000 67.000 67.000 6.000 7.000 1.795 62.250 °C
Temp LM18 62.000 62.000 62.000 64.000 73.000 73.000 73.000 11.000 11.000 3.857 65.363 °C
Temp LM19 55.000 55.000 55.000 57.000 65.000 65.000 65.000 10.000 10.000 3.245 58.116 °C
Temp LM2 44.000 44.000 45.000 46.000 46.000 46.000 47.000 1.000 2.000 0.602 45.521 °C
Temp LM20 27.000 28.000 28.000 30.000 33.000 36.000 36.000 5.000 8.000 1.694 30.032 °C
Temp LM21 27.000 27.000 28.000 29.000 32.000 35.000 36.000 4.000 8.000 1.646 29.644 °C
Temp LM22 24.000 25.000 26.000 28.000 31.000 33.000 35.000 5.000 8.000 1.778 28.137 °C
Temp LM23 27.000 27.000 27.000 29.000 33.000 36.000 36.000 6.000 9.000 1.743 29.528 °C
Temp LM24 26.000 26.000 27.000 29.000 32.000 33.000 35.000 5.000 7.000 1.654 28.989 °C
Temp LM3 33.000 33.000 33.000 34.000 35.000 35.000 35.000 2.000 2.000 0.647 34.063 °C
Temp LM4 31.500 31.500 31.500 32.500 33.500 33.500 34.000 2.000 2.000 0.649 32.653 °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 60.000 60.000 60.000 61.000 66.000 67.000 67.000 6.000 7.000 1.841 62.077 °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 27.000 28.000 28.000 29.000 33.000 34.000 36.000 5.000 6.000 1.532 29.792 °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 60.000 60.000 60.000 61.500 66.000 67.000 67.000 6.000 7.000 1.820 62.245 °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) -175.490 -156.778 -125.887 29.736 109.448 190.028 222.603 235.335 346.806 83.962 11.102 µs -0.3058 2.092

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 -420.288 -379.941 -352.570 15.800 224.870 234.600 244.954 577.440 614.541 189.848 -10.713 µs -0.4039 1.921

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 -113.658 -56.284 -26.203 50.990 95.632 182.495 203.057 121.835 238.779 38.968 47.579 µs -0.0001204 5.936

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 -440.052 -190.977 -21.635 40.107 121.291 170.001 349.356 142.926 360.978 56.882 38.343 µs -2.33 27.38

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) -97.828 -91.504 -36.969 -0.853 29.289 112.464 135.841 66.258 203.968 26.683 -0.160 µs 0.6378 10.55

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) 1.607 4.028 6.063 36.386 96.796 111.469 122.757 90.733 107.441 28.238 39.329 µs 0.6613 2.591

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 4.160 4.890 6.824 14.373 31.003 43.136 61.954 24.179 38.246 7.675 16.168 µs 1.632 7.172

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 1.986 3.494 4.964 20.390 52.044 76.715 102.737 47.080 73.221 14.954 22.951 µs 1.5 6.578

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 4.133 6.896 15.141 99.990 162.177 196.351 335.253 147.036 189.455 45.927 95.452 µs 0.06148 3.597

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) 0.348 0.490 0.753 2.260 10.985 33.432 68.982 10.232 32.942 5.986 3.757 µs 6.13 50.7

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 11.792 11.793 11.807 12.095 12.323 12.333 12.334 0.516 0.540 0.153 12.072 ppm -0.2195 2.149
Local Clock Time Offset -97.827 -91.503 -36.968 -0.852 29.288 112.463 135.840 66.256 203.966 26.683 -0.160 µs 0.6378 10.55
Local RMS Frequency Jitter 0.128 0.155 0.220 0.712 4.278 6.528 7.322 4.058 6.373 1.222 1.077 ppb 2.915 11.72
Local RMS Time Jitter 0.447 0.549 0.633 0.958 3.540 7.830 12.492 2.907 7.281 1.392 1.470 µs 3.909 22.78
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 1.607 4.028 6.063 36.386 96.796 111.469 122.757 90.733 107.441 28.238 39.329 µs 0.6613 2.591
Server Jitter 204.17.205.1 4.160 4.890 6.824 14.373 31.003 43.136 61.954 24.179 38.246 7.675 16.168 µs 1.632 7.172
Server Jitter 204.17.205.24 1.986 3.494 4.964 20.390 52.044 76.715 102.737 47.080 73.221 14.954 22.951 µs 1.5 6.578
Server Jitter 204.17.205.27 4.133 6.896 15.141 99.990 162.177 196.351 335.253 147.036 189.455 45.927 95.452 µs 0.06148 3.597
Server Jitter SHM(0) 0.348 0.490 0.753 2.260 10.985 33.432 68.982 10.232 32.942 5.986 3.757 µs 6.13 50.7
Server Offset 2001:470:e815::8 (spidey.rellim.com) -175.490 -156.778 -125.887 29.736 109.448 190.028 222.603 235.335 346.806 83.962 11.102 µs -0.3058 2.092
Server Offset 204.17.205.1 -420.288 -379.941 -352.570 15.800 224.870 234.600 244.954 577.440 614.541 189.848 -10.713 µs -0.4039 1.921
Server Offset 204.17.205.24 -113.658 -56.284 -26.203 50.990 95.632 182.495 203.057 121.835 238.779 38.968 47.579 µs -0.0001204 5.936
Server Offset 204.17.205.27 -440.052 -190.977 -21.635 40.107 121.291 170.001 349.356 142.926 360.978 56.882 38.343 µs -2.33 27.38
Server Offset SHM(0) -97.828 -91.504 -36.969 -0.853 29.289 112.464 135.841 66.258 203.968 26.683 -0.160 µs 0.6378 10.55
Temp /dev/sda 44.000 44.000 45.000 46.000 47.000 49.000 49.000 2.000 5.000 0.794 45.687 °C
Temp /dev/sdb 55.000 55.000 55.000 56.000 65.000 65.000 65.000 10.000 10.000 3.268 57.989 °C
Temp /dev/sdc 56.000 56.000 56.000 56.000 58.000 61.000 61.000 2.000 5.000 1.034 56.658 °C
Temp /dev/sdd 62.000 62.000 62.000 63.000 73.000 73.000 73.000 11.000 11.000 3.847 65.229 °C
Temp /dev/sde 44.000 44.000 44.000 46.000 46.000 47.000 47.000 2.000 3.000 0.631 45.496 °C
Temp /dev/sdf 56.000 56.000 56.000 57.000 65.000 65.000 65.000 9.000 9.000 3.289 58.535 °C
Temp LM0 28.750 28.750 29.000 30.250 32.250 33.250 34.000 3.250 4.500 1.055 30.446 °C
Temp LM1 40.000 40.000 40.000 41.500 42.000 42.500 42.500 2.000 2.500 0.606 41.303 °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 44.000 44.000 45.000 46.000 47.000 49.000 49.000 2.000 5.000 0.798 45.690 °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 30.000 30.000 30.250 31.500 33.000 33.750 34.250 2.750 3.750 0.867 31.563 °C
Temp LM16 56.000 56.000 56.000 57.000 65.000 65.000 65.000 9.000 9.000 3.247 58.651 °C
Temp LM17 60.000 60.000 60.000 61.500 66.000 67.000 67.000 6.000 7.000 1.795 62.250 °C
Temp LM18 62.000 62.000 62.000 64.000 73.000 73.000 73.000 11.000 11.000 3.857 65.363 °C
Temp LM19 55.000 55.000 55.000 57.000 65.000 65.000 65.000 10.000 10.000 3.245 58.116 °C
Temp LM2 44.000 44.000 45.000 46.000 46.000 46.000 47.000 1.000 2.000 0.602 45.521 °C
Temp LM20 27.000 28.000 28.000 30.000 33.000 36.000 36.000 5.000 8.000 1.694 30.032 °C
Temp LM21 27.000 27.000 28.000 29.000 32.000 35.000 36.000 4.000 8.000 1.646 29.644 °C
Temp LM22 24.000 25.000 26.000 28.000 31.000 33.000 35.000 5.000 8.000 1.778 28.137 °C
Temp LM23 27.000 27.000 27.000 29.000 33.000 36.000 36.000 6.000 9.000 1.743 29.528 °C
Temp LM24 26.000 26.000 27.000 29.000 32.000 33.000 35.000 5.000 7.000 1.654 28.989 °C
Temp LM3 33.000 33.000 33.000 34.000 35.000 35.000 35.000 2.000 2.000 0.647 34.063 °C
Temp LM4 31.500 31.500 31.500 32.500 33.500 33.500 34.000 2.000 2.000 0.649 32.653 °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 60.000 60.000 60.000 61.000 66.000 67.000 67.000 6.000 7.000 1.841 62.077 °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 27.000 28.000 28.000 29.000 33.000 34.000 36.000 5.000 6.000 1.532 29.792 °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 60.000 60.000 60.000 61.500 66.000 67.000 67.000 6.000 7.000 1.820 62.245 °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!