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