On Wed, Jul 4, 2012 at 11:06 PM, Mauro Santos <registo.mailling@xxxxxxxxx> wrote: > On 04-07-2012 21:00, Tom Gundersen wrote: >> On Wed, Jul 4, 2012 at 9:06 PM, Kevin Chadwick <ma1l1ists@xxxxxxxxxxx> wrote: >>>> If you have a >>>> mercurial/git installation even in a small group, I am sure you'll prefer >>>> accurate timestamps in your commit history. And the list goes on... >>> >>> I believe an RTC is perfectly capable of that. >> >> I tried to find some data on what to expect from RTC's. I was not very >> successful, except finding people citing 80-100PPM as typical drift >> rates (~8 secs/day). > > From data I have access to, taken from machines running ntpd, I can say > the following about the drift in PPM stored in ntpd's drift file: > > my laptop: -9.699 > machine 1: -8.762 > machine 2: -443.266 > machine 3: -35.417 > > Machine 1 is the newest and machine 3 is the oldest. One more data point: my wrist watch is off by about 20ppm (unless I forget to wind it, then it is more ;-) ). -t
