[varjag]

PTP at this point is ubiquitous and cheap. It is hard to source a PHY that has no support for it in 2021.

> If they had the same support for NTP, it would perform as well.

Unless you'd extend NTP to become PTP, it absolutely wouldn't.

[mlichvar]

Yes, NICs with support for hardware timestamping are common (it's typically in the MAC, not PHY), but switches that have a good support for PTP, either as a boundary clock, or transparent clock, are not cheap. At least I have not seen one yet. Do you have any examples?

Some switches support NTP as a server and client (equivalent to the PTP boundary clock), but there don't seem to be any using hardware timestamping. It's just the classic ntpd using software timestamps, good to few tens of microseconds at best.

And yes, NTP could definitely perform as well as PTP if the switches had a proper support. In my tests with directly connected NICs the synchronization is stable to few nanoseconds, same as with PTP. At the protocol level, they use the same timestamps.

[varjag]

> Do you have any examples?

Probably all current Cisco offerings? Ubiquiti industrial switches? A whole crowd of second tier vendors like Lantech or Korenix? These are just those I had direct experience with.

Of these, Cisco definitely does boundary clock on L3, on at least several models of their routers.

> In my tests with directly connected NICs the synchronization is stable to few nanoseconds, same as with PTP.

Yes network sync is piece of cake if you drop the whole network bit. That said am slightly skeptical about ns level precision with NTP. Did you measure synchronicity between the two devices via scope?