Ethernet bandwidth is not achieving 1Gbps, 345Mbps Only

[JWii.1]

I got my STM32MP157A-DK1 load STM32MP15-Ecosystem-v2.1.0/Starter-Package

Using iPerf3 for UDP speed test, but only achieved around 345Mbps.

Made sure the cable, labtop NIC, switch are compatible with Gigabit.

Attching board eth0 config

Settings for eth0:

       Supported ports: [ TP MII ]

       Supported link modes:  10baseT/Half 10baseT/Full

                               100baseT/Half 100baseT/Full

                               1000baseT/Full

       Supported pause frame use: Symmetric Receive-only

       Supports auto-negotiation: Yes

       Supported FEC modes: Not reported

       Advertised link modes: 10baseT/Half 10baseT/Full

                               100baseT/Half 100baseT/Full

                               1000baseT/Full

       Advertised pause frame use: Symmetric Receive-only

       Advertised auto-negotiation: Yes

       Advertised FEC modes: Not reported

       Link partner advertised link modes: 10baseT/Half 10baseT/Full

                                            100baseT/Half 100baseT/Full

                                            1000baseT/Full

       Link partner advertised pause frame use: Symmetric

       Link partner advertised auto-negotiation: Yes

       Link partner advertised FEC modes: Not reported

       Speed: 1000Mb/s

       Duplex: Full

       Port: MII

       PHYAD: 0

       Transceiver: internal

       Auto-negotiation: on

       Supports Wake-on: ug

       Wake-on: d

       Current message level: 0x0000003f (63)

                              drv probe link timer ifdown ifup

       Link detected: yes

Attaching iperf3 test result

./iperf3 -c 10.0.0.169 -u -b 1G

Connecting to host 10.0.0.169, port 5201

[ 4] local 10.0.0.5 port 51001 connected to 10.0.0.169 port 5201

[ ID] Interval          Transfer    Bandwidth      Total Datagrams

[ 4]  0.00-1.00  sec 38.3 MBytes  321 Mbits/sec 4897

[ 4]  1.00-2.00  sec 40.8 MBytes  342 Mbits/sec 5225

[ 4]  2.00-3.00  sec 42.4 MBytes  355 Mbits/sec 5421

[ 4]  3.00-4.00  sec 41.1 MBytes  344 Mbits/sec 5255

[ 4]  4.00-5.00  sec 42.0 MBytes  352 Mbits/sec 5375

[ 4]  5.00-6.00  sec 41.2 MBytes  346 Mbits/sec 5279

[ 4]  6.00-7.00  sec 41.8 MBytes  351 Mbits/sec 5350

[ 4]  7.00-8.00  sec 41.3 MBytes  346 Mbits/sec 5283

[ 4]  8.00-9.00  sec 42.0 MBytes  353 Mbits/sec 5375

[ 4]  9.00-10.00 sec 40.8 MBytes  342 Mbits/sec 5226

- - - - - - - - - - - - - - - - - - - - - - - - -

[ ID] Interval          Transfer    Bandwidth      Jitter   Lost/Total Datagrams

[ 4]  0.00-10.00 sec  412 MBytes  345 Mbits/sec 0.204 ms 1805/52659 (3.4%)

[ 4] Sent 52659 datagrams

Please contribute you ideas on what am I missing? what else can I further do?

[Bernard PUEL]

Hello,

We did check the tests performed on V2.1.0. And the performances were very good on MP157f DK2 (so near 950 MB).

1/ MP157f is 800Mhz and dual cpu, so this can explain the diff. You can check adding "-V" option in Iperf3 the cpu load used (even if sometimes the value in not correct).

2/ Our tests are performed on a private LAN with only 2 boards inside the gateway LAN (one for Ref and the tested board). This can also influence the results.

3/ Iperf3 versions need to be the same or very close between the server and client (we have also seen big diff around this).

4/ With net data server, you can easily double check the iperf3 output data: see https://wiki.st.com/stm32mpu/wiki/Netdata.

[Bernard PUEL]

Coming back to this subject. The picture is not so easy to get and we can see a regression between kernel 4.9 (V1.x.y) and 5.10 (V3.x.y) with same setup.

Analysis is ongoing. The issue is not related to cpu bandwidth (no limitation seen on MP157F ).

[Bernard PUEL]

I mean 4.9 and 5.10 is ok but 5.4 is below 400 Mbits/sec.