Constraints

Enhanced PTP User Guide (UG1602)

Document ID
UG1602
Release Date
2023-04-07
Revision
1.1 English

Chronyd has various performance limitations:

  • The chronyd daemon disciplines only the system clock, and sfptpd disciplines the remainder of the clocks from the system clock.
  • The chronyd daemon tends to slew the system clock rapidly for a short period of time every few minutes (for example 20).

    The result can be periodic errors between the system and NIC clocks, while the adapter clocks catch up with this rapid change in the system clock. The behavior will get better over time. For example, once the host has been up for 24 hours the NTP adjustments will be much smaller.

  • The accuracy of NTP can vary massively. AMD recommend only using this mode with a GPS-connected NTP server.