On Mon, Jun 26, 2017 at 9:28 AM, Chris Perl <cp...@janestreet.com> wrote: >> The reason why they are always 15 microseconds is that the fields have >> a 32-bit fixed-point format with ~15 microsecond resolution and >> chronyd as a server rounds them up. So, if it calculates its delay and >> dispersion as 1 microsecond, they will still be rounded to 15 >> microseconds. It's a limitation of the NTPv4 protocol. I'd like to >> improve this in NTPv5 when the NTP WG starts working on a new version. >> >> If you wanted to get a more accurate root distance on the client, you >> could set the delay of the SHM refclock on the server to 0 and add >> half of the delay to the precision instead. I think it might have a >> small effect on the timekeeping performance though. > > That is very helpful. Thanks!
Are there any similar tricks to be able to get a more accurate root dispersion on clients? In the setup I've been testing, chrony on the server generally reports a root dispersion of about 1us. But, this is getting rounded up to 15us due to the aforementioned fixed-point format. -- To unsubscribe email chrony-users-requ...@chrony.tuxfamily.org with "unsubscribe" in the subject. For help email chrony-users-requ...@chrony.tuxfamily.org with "help" in the subject. Trouble? Email listmas...@chrony.tuxfamily.org.
