Hi,
I have a PTP-ish implementation, here, that I use to ensure all nodes in distributed ("proprietary") system have a consistent notion of "now". I.e., I can order to arbitrary events originating on two different nodes with a very small window of uncertainty (chicken vs egg).
But, I've done this *without* "PTP-enabled" NICs. (because I control the traffic on the wire -- as well as stuff getting onto it and coming off of it!)
This gives me greater flexibility in picking target hardware on which to deploy (as well as letting me save money by avoiding "specialty" SoC's).
I'd like to get an idea FROM FOLKS WITH ACTUAL PTP (or equivalent) IMPLEMENTATIONS as to the level of "long term" synchronization they've been able to achieve. And, ideally, if they've experimented with disabling (i.e., implementing alternative mechanisms) the hardware timestamp common in PTP-enabled NICs -- to see just what that feature has
*bought* them. [Of course, I realize this will probably yield a dramatic decrease in precision because the rest of the implementation *relied* on this in lieu of timeliness]What I'm trying to do is get a handle on what possible
*increase* in precision I could gain by adopting such NICs in my design (which would require recoding some parts of it). This at the expense of LIMITING my hardware choices.Thx,
--don