Jetson TX1 strange network performance behaviour (still)

I have a TX2 connected at the moment (R28.2), so I’ll add results for this as well as a TX1. When running Jetson as (“tx2” is my host alias for the TX2):

iperf3 -s

…host PC as:

iperf3 -c x2 -u -b 0 -l 16k -t 120 -i 1

I see this from the TX2:

[ ID] Interval           Transfer     Bandwidth       Jitter    Lost/Total Datagrams
[  5]   0.00-120.04 sec  7.57 GBytes   542 Mbits/sec  0.201 ms  4669/496378 (0.94%)

…this from the PC:

[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-120.00 sec  7.57 GBytes   542 Mbits/sec  0.000 ms  0/496380 (0%)  sender
[  5]   0.00-120.00 sec  7.50 GBytes   537 Mbits/sec  0.201 ms  4669/496378 (0.94%)  receiver

There is some packet loss, but only from the perspective of iperf3 (ifconfig did not show a loss).

Switching to TX1 (under R28.2)…

Jetson command:

iperf3 -s

PC command (“x1” is my host alias for the TX1):

iperf3 -c x1 -u -b 0 -l 16k -t 120 -i 1

This is from the TX1:

[ ID] Interval           Transfer     Bandwidth       Jitter    Lost/Total Datagrams
[  5]   0.00-120.04 sec  7.78 GBytes   557 Mbits/sec  0.300 ms  1123/510179 (0.22%)

This is from the PC:

[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-120.00 sec  7.78 GBytes   557 Mbits/sec  0.000 ms  0/510180 (0%)  sender
[  5]   0.00-120.00 sec  7.77 GBytes   556 Mbits/sec  0.300 ms  1123/510179 (0.22%)  receiver

Loss is shown in iperf3. No loss was shown from ifconfig.

Neither PC nor Jetson had any significant load going on during the test. Network is a private gigabit LAN using its own NIC and gigabit switch.

In neither case did I test the reverse direction this time since in the past this has not resulted in slow-down or loss. Let me know if you want a different test.