NTPsec

Kong

Report generated: Wed May 18 13:59:02 2022 UTC
Start Time: Wed May 11 13:59:01 2022 UTC
End Time: Wed May 18 13:59:01 2022 UTC
Report Period: 7.0 days

Daily stats   Weekly stats   Live GNSS Data   24 Hour Scatter Plots: ( )

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 -180.853 -59.085 -35.219 -1.226 38.181 71.533 241.828 73.400 130.618 25.512 -0.199 µs -3.433 17.18
Local Clock Frequency Offset 9.434 9.497 9.748 10.206 10.783 10.867 11.140 1.035 1.371 0.324 10.240 ppm 2.865e+04 8.786e+05

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 0.060 9.608 11.460 17.885 29.062 39.566 54.900 17.602 29.958 5.836 18.811 µs 19.12 74.07

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 3.808 4.878 9.503 22.829 44.229 70.586 17.951 40.421 7.218 11.237 ppb 5.037 26.81

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 -180.853 -59.085 -35.219 -1.226 38.181 71.533 241.828 73.400 130.618 25.512 -0.199 µs -3.433 17.18

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 9.434 9.497 9.748 10.206 10.783 10.867 11.140 1.035 1.371 0.324 10.240 ppm 2.865e+04 8.786e+05
Temp /dev/sda 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp /dev/sdb 46.000 46.000 47.000 48.000 50.000 51.000 52.000 3.000 5.000 1.041 48.248 °C
Temp /dev/sdc 33.000 34.000 34.000 36.000 38.000 39.000 40.000 4.000 5.000 1.225 35.979 °C
Temp /dev/sdd 24.000 24.000 25.000 26.000 31.000 32.000 33.000 6.000 8.000 2.234 27.471 °C
Temp /dev/sde 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM0 49.000 49.000 50.000 54.000 58.000 59.000 59.000 8.000 10.000 2.871 53.893 °C
Temp LM1 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM2 33.000 34.000 34.000 36.000 38.000 39.000 39.000 4.000 5.000 1.214 36.041 °C
Temp LM3 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM4 76.375 76.750 77.375 78.750 83.250 84.750 90.875 5.875 8.000 1.663 79.042 °C
Temp LM5 64.750 76.250 77.000 78.500 82.250 84.500 90.250 5.250 8.250 1.642 78.759 °C
Temp LM6 24.000 24.000 25.000 27.000 31.000 32.000 36.000 6.000 8.000 2.260 27.574 °C
Temp LM7 46.000 46.000 47.000 48.000 50.000 51.000 52.000 3.000 5.000 1.033 48.250 °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.



Local GPS

local gps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
nSats 0.000 0.000 0.000 0.000 0.000 0.000 12.000 0.000 0.000 0.062 0.000 nSat 173.2 3.123e+04
TDOP 0.740 0.830 0.920 1.380 2.290 3.070 10.320 1.370 2.240 0.462 1.468 19.3 92.85

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



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::24 (pi4.rellim.com)

peer offset 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::24 (pi4.rellim.com) -0.194 -0.067 -0.037 0.024 0.078 0.114 169.264 0.115 0.182 2.639 0.064 ms 60.23 3866

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 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) -1.363 -1.131 -0.619 0.064 0.393 0.558 168.828 1.011 1.689 5.165 0.161 ms 28.69 941.9

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 -1.365 -1.140 -0.670 0.025 0.363 0.612 168.793 1.033 1.751 2.652 0.008 ms 58.73 3748

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 204.17.205.17

peer offset 204.17.205.17 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.17 -0.410 -0.097 -0.032 0.029 0.092 0.152 169.204 0.124 0.249 4.489 0.149 ms 33.79 1276

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 204.17.205.23

peer offset 204.17.205.23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.23 -0.246 -0.090 -0.062 -0.016 0.039 0.079 168.881 0.101 0.168 3.707 0.067 ms 41.62 1901

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 204.17.205.30

peer offset 204.17.205.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.30 -0.227 -0.111 -0.051 -0.003 0.039 0.080 168.916 0.090 0.191 3.794 0.080 ms 40.6 1811

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer offset 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -2.699 -2.277 -1.473 -0.716 0.049 0.445 168.616 1.522 2.722 3.865 -0.615 ms 38.08 1698

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 2606:4700:f1::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -0.722 0.431 1.014 1.859 2.120 2.297 171.055 1.106 1.865 4.311 1.871 ms 37.06 1442

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 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 1.407 1.535 1.607 1.883 2.113 2.210 2.513 0.505 0.675 0.152 1.875 ms 1505 1.751e+04

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) -176.731 -148.262 -143.889 -131.628 -126.249 -124.804 33.346 17.641 23.458 5.342 -132.660 ms -1.732e+04 4.495e+05

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(2)

peer offset SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(2) 1,295.199 1,304.772 1,343.104 1,774.439 2,205.661 2,243.999 2,253.570 862.557 939.228 276.661 1,774.416 s 174.9 1037

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::24 (pi4.rellim.com)

peer jitter 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.000 5.565 8.042 22.832 69.675 98.907 939.452 61.633 93.342 35.162 30.930 µs 9.559 165.2

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 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 4.756 6.551 13.942 43.787 70.935 125.869 37.236 66.179 13.067 18.096 µs 3.825 17.96

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 3.511 5.013 13.809 38.948 61.421 149.369 33.935 57.910 12.461 17.044 µs 3.852 21.76

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 204.17.205.17

peer jitter 204.17.205.17 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.17 0.000 7.407 11.024 28.064 75.577 114.892 2,855.661 64.553 107.485 83.173 36.720 µs 26.35 858.9

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 204.17.205.23

peer jitter 204.17.205.23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.23 0.000 6.346 9.366 23.045 52.759 82.595 2,198.897 43.393 76.249 57.528 28.592 µs 26.34 926.7

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 204.17.205.30

peer jitter 204.17.205.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.30 0.000 4.637 6.146 17.859 55.167 86.095 222.946 49.021 81.458 18.244 22.913 µs 3.945 25.9

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer jitter 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.000 0.279 0.456 1.448 5.120 15.941 41.340 4.664 15.662 3.205 2.147 ms 6.046 59.1

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 2606:4700:f1::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.000 0.155 0.225 0.537 1.424 11.148 28.877 1.199 10.993 1.782 0.816 ms 7.563 83.81

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 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.141 0.155 0.239 0.515 1.354 2.508 11.184 1.115 2.354 0.927 0.679 ms 7.966 83.38

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) 0.000 0.305 0.458 1.579 10.046 12.812 166.413 9.588 12.507 3.806 3.309 ms 8.469 270.5

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(2)

peer jitter SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(2) 0.000 55.299 55.542 56.716 57.854 58.072 60.073 2.311 2.772 0.912 56.696 ms 2.289e+05 1.401e+07

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 9.434 9.497 9.748 10.206 10.783 10.867 11.140 1.035 1.371 0.324 10.240 ppm 2.865e+04 8.786e+05
Local Clock Time Offset -180.853 -59.085 -35.219 -1.226 38.181 71.533 241.828 73.400 130.618 25.512 -0.199 µs -3.433 17.18
Local RMS Frequency Jitter 0.000 3.808 4.878 9.503 22.829 44.229 70.586 17.951 40.421 7.218 11.237 ppb 5.037 26.81
Local RMS Time Jitter 0.060 9.608 11.460 17.885 29.062 39.566 54.900 17.602 29.958 5.836 18.811 µs 19.12 74.07
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.000 5.565 8.042 22.832 69.675 98.907 939.452 61.633 93.342 35.162 30.930 µs 9.559 165.2
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 0.000 4.756 6.551 13.942 43.787 70.935 125.869 37.236 66.179 13.067 18.096 µs 3.825 17.96
Server Jitter 204.17.205.1 0.000 3.511 5.013 13.809 38.948 61.421 149.369 33.935 57.910 12.461 17.044 µs 3.852 21.76
Server Jitter 204.17.205.17 0.000 7.407 11.024 28.064 75.577 114.892 2,855.661 64.553 107.485 83.173 36.720 µs 26.35 858.9
Server Jitter 204.17.205.23 0.000 6.346 9.366 23.045 52.759 82.595 2,198.897 43.393 76.249 57.528 28.592 µs 26.34 926.7
Server Jitter 204.17.205.30 0.000 4.637 6.146 17.859 55.167 86.095 222.946 49.021 81.458 18.244 22.913 µs 3.945 25.9
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.000 0.279 0.456 1.448 5.120 15.941 41.340 4.664 15.662 3.205 2.147 ms 6.046 59.1
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.000 0.155 0.225 0.537 1.424 11.148 28.877 1.199 10.993 1.782 0.816 ms 7.563 83.81
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.141 0.155 0.239 0.515 1.354 2.508 11.184 1.115 2.354 0.927 0.679 ms 7.966 83.38
Server Jitter SHM(0) 0.000 0.305 0.458 1.579 10.046 12.812 166.413 9.588 12.507 3.806 3.309 ms 8.469 270.5
Server Jitter SHM(2) 0.000 55.299 55.542 56.716 57.854 58.072 60.073 2.311 2.772 0.912 56.696 ms 2.289e+05 1.401e+07
Server Offset 2001:470:e815::24 (pi4.rellim.com) -0.194 -0.067 -0.037 0.024 0.078 0.114 169.264 0.115 0.182 2.639 0.064 ms 60.23 3866
Server Offset 2001:470:e815::8 (spidey.rellim.com) -1.363 -1.131 -0.619 0.064 0.393 0.558 168.828 1.011 1.689 5.165 0.161 ms 28.69 941.9
Server Offset 204.17.205.1 -1.365 -1.140 -0.670 0.025 0.363 0.612 168.793 1.033 1.751 2.652 0.008 ms 58.73 3748
Server Offset 204.17.205.17 -0.410 -0.097 -0.032 0.029 0.092 0.152 169.204 0.124 0.249 4.489 0.149 ms 33.79 1276
Server Offset 204.17.205.23 -0.246 -0.090 -0.062 -0.016 0.039 0.079 168.881 0.101 0.168 3.707 0.067 ms 41.62 1901
Server Offset 204.17.205.30 -0.227 -0.111 -0.051 -0.003 0.039 0.080 168.916 0.090 0.191 3.794 0.080 ms 40.6 1811
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -2.699 -2.277 -1.473 -0.716 0.049 0.445 168.616 1.522 2.722 3.865 -0.615 ms 38.08 1698
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -0.722 0.431 1.014 1.859 2.120 2.297 171.055 1.106 1.865 4.311 1.871 ms 37.06 1442
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 1.407 1.535 1.607 1.883 2.113 2.210 2.513 0.505 0.675 0.152 1.875 ms 1505 1.751e+04
Server Offset SHM(0) -176.731 -148.262 -143.889 -131.628 -126.249 -124.804 33.346 17.641 23.458 5.342 -132.660 ms -1.732e+04 4.495e+05
Server Offset SHM(2) 1,295.199 1,304.772 1,343.104 1,774.439 2,205.661 2,243.999 2,253.570 862.557 939.228 276.661 1,774.416 s 174.9 1037
TDOP 0.740 0.830 0.920 1.380 2.290 3.070 10.320 1.370 2.240 0.462 1.468 19.3 92.85
Temp /dev/sda 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp /dev/sdb 46.000 46.000 47.000 48.000 50.000 51.000 52.000 3.000 5.000 1.041 48.248 °C
Temp /dev/sdc 33.000 34.000 34.000 36.000 38.000 39.000 40.000 4.000 5.000 1.225 35.979 °C
Temp /dev/sdd 24.000 24.000 25.000 26.000 31.000 32.000 33.000 6.000 8.000 2.234 27.471 °C
Temp /dev/sde 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM0 49.000 49.000 50.000 54.000 58.000 59.000 59.000 8.000 10.000 2.871 53.893 °C
Temp LM1 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM2 33.000 34.000 34.000 36.000 38.000 39.000 39.000 4.000 5.000 1.214 36.041 °C
Temp LM3 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 °C
Temp LM4 76.375 76.750 77.375 78.750 83.250 84.750 90.875 5.875 8.000 1.663 79.042 °C
Temp LM5 64.750 76.250 77.000 78.500 82.250 84.500 90.250 5.250 8.250 1.642 78.759 °C
Temp LM6 24.000 24.000 25.000 27.000 31.000 32.000 36.000 6.000 8.000 2.260 27.574 °C
Temp LM7 46.000 46.000 47.000 48.000 50.000 51.000 52.000 3.000 5.000 1.033 48.250 °C
nSats 0.000 0.000 0.000 0.000 0.000 0.000 12.000 0.000 0.000 0.062 0.000 nSat 173.2 3.123e+04
Summary as CSV file


This server:

Motherboard:
OS: Gentoo unstable
GPS:
GPS/PPS server: gpsd
NTP server: NTPsec
../ntp.conf

Notes:

Feb 21 03:28:57 UTC 2019: New install

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.
kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of 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".
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 Pearson's moment coefficient of skewness. Wikipedia describes it best: "The qualitative interpretation of the skew is complicated and unintuitive."
A normal distribution has a skewness of zero.
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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