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. > Having a look at my own machine (a reasonably new Dell laptop) I don't > see values quite that bad. I lose about 14 PPM, which amounts to > roughly seven minutes in a year. > > Having that kind of discrepancies on a network doing distributed > development would wreck absolute havoc. > > -t > -- Mauro Santos
