Both the ConnectX-5 in Option 1 and the ConnectX-7 in Option 2 support hardware timestamping. Both options use the same PTP settings, with different Linux interface names. Hardware timestamping records packet timing at the NIC, reducing timing uncertainty introduced by operating system scheduling and software processing.
Set the host’s priority1 and priority2 values to 10 so it is preferred over cameras using the default priority of 128. Lower numerical values indicate higher priority. This helps keep the host as the grandmaster for both camera VLANs.
Create a PTP configuration file named: grandmaster.cfg
[global]verbose 1boundary_clock_jbod 1time_stamping hardwaretx_timestamp_timeout 50priority1 10priority2 10domainNumber 0logAnnounceInterval 1logSyncInterval 0logMinDelayReqInterval 0announceReceiptTimeout 3delay_mechanism E2Enetwork_transport UDPv4# Include the interface pair for your selected option# Option 1: Discrete GPU:[enp1s0f0np0][enp1s0f1np1]# Option 2: DGX Spark:[enp1s0f0np0][enP2p1s0f1np1]
Run PTP grandmaster
$ sudo ptp4l -f grandmaster.cfg -m
Keep ptp4l running and open a second terminal.
# Run in a second terminal while ptp4l remains running$ sudo phc2sys -a -r
phc2sys -a will obtain the clock configuration from the running ptp4l process and follow its port states. The -r option also includes the system clock in synchronization. This is needed for our existing boundary_clock_jbod 1 configuration, where separate port hardware clocks need synchronization.