On 10/05/2011 22:36, Stan Hoeppner wrote: > On 5/10/2011 8:50 AM, Ed W wrote: > >> So, in practice it's fairly irrelevant to be hooked to a stratum 1 for >> most purposes and if you really want to get obsessed about accurate time >> (I'm going through this obsession phase right now...) then just get a >> local GPS attached to your machine... > > NTP is free and the accuracy, when properly configured, is better than > that required by any network application. If your goal is sub > millisecond accuracy, it's not due to any actual network application > requirement.
I'm not sure if I understand your point? My point was that some Stratum 1 servers are less than 1ms accurate. You were making excited noises about being given access to a Stratum 1 server via an internet connection and I was simply pointing out that such a setup does not necessarily give super accurate time at your side (especially compared with adding a $50 GPS to a local machine - which of course makes that machine a stratum 1) Also, I don't understand your point about NTP being free? Chrony is GPL? Finally you say that NTP is "better than required", but in fact NTP can often take quite a long time to converge to fairly accurate time? If the machine is rebooted (less common for a server, but more common for desktop machines), and the RTC is inaccurate, then it can take quite a long time each boot before the clock is decent. One citation here: http://lists.ntp.org/pipermail/questions/2011-April/029223.html Chrony converges much more rapidly in general NTP is clearly "good enough", I was just trying to bring other ideas to the attention of the OP (and now you). Chrony is a very good solution and solves a number of problems with timekeeping that perhaps you were not even aware that you had? Kind regards Ed W