71–80 of 162 posts
Not exactly the topic of discussion but also not not on topic: just wanted to sing praise for chrony which has performed better than the traditional os-native NTP clients in our testing on a myriad of real and virtualized hardware.
Out of curiosity, can anyone say the most impactful things they've needed incredibly accurate time for?
Spanner (See https://docs.cloud.google.com/spanner/docs/true-time-externa... )
Earlier quoted context omitted.
> I never saw a need for this in HFT. In my experience, GPS was used instead, but there was never any critical need for microsecond accuracy in live systems. mifid ii (uk/eu) minimum is 1us granularity https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:...
It's 1 us granularity , which means you should report your timestamps with six figures after the decimal point. The required accuracy (Tables 1 and 2 in that document) is 100 us or 1000 us depending on the system.
no, Tables 1 and 2 say divergence, not accuracy
accuracy is a mix of both granularity and divergence
regardless, your statement before:
> The regulatory requirement you linked (and other typical requirements from regulators) allows a tolerance of one second, so it doesn't call for this kind of technology.
is not true
I found the most interesting part of the NIST outage post [1] is NIST's special Time Over Fiber (TOF) program [2] that "provides high-precision time transfer by other service arrangements; some direct fiber-optic links were affected and users will be contacted separately." I've never heard of this! Very cool service, presumably for … quant / HFT / finance firms (maybe for compliance with FINRA Rule 4590 [3])? Telecom…
Has anyone here ever needed microsecond precision? Would love to hear about it.
Nitpick: UTC stands for Coordinated Universal Time. The ordering of the letters was chosen to not match the English or the French names so neither language got preference.
Only Boulder servers lost sync. To say NIST was off is clickbait hyperbole. This page: https://tf.nist.gov/tf-cgi/servers.cgi shows that NIST has > 16 NTP servers on IPv4, of those, 5 are in Boulder and were affected by the power failure. The rest were fine. However, most entities should not be using these top-level servers anyway, so this should have been a problem for exactly nobody. IMHO, most applications should…
Is pool.ntp.org dispersed across possible interference and error correlation?
Nitpick: UTC stands for Coordinated Universal Time. The ordering of the letters was chosen to not match the English or the French names so neither language got preference.
Nitpick: UTC stands for Coordinated Universal Time. The ordering of the letters was chosen to not match the English or the French names so neither language got preference.
I found the most interesting part of the NIST outage post [1] is NIST's special Time Over Fiber (TOF) program [2] that "provides high-precision time transfer by other service arrangements; some direct fiber-optic links were affected and users will be contacted separately." I've never heard of this! Very cool service, presumably for … quant / HFT / finance firms (maybe for compliance with FINRA Rule 4590 [3])? Telecom…
To start with, probably for scientific stuff, à la:
* https://en.wikipedia.org/wiki/White_Rabbit_Project
But fibre-based time is important in case of GNSS time signal loss:
* https://www.gpsworld.com/china-finishing-high-precision-grou...