Ethernet throughput: Upload speeds are slow

[stevekim]

I have been doing some preliminary testing using the iMX6Q Sabre Platform.  Using iperf, I am getting speeds of around 425Mbps, which is expected for gigabit Ethernet.  However, on uploads, I am only seeing speeds at around 60Mbps.  To restate, here are the commands I am using:

iperf -c <server_ip> -i 2 -p 50000 -t 20  ====> ~425Mbps

iperf -s -i 2 -p 50000                           ====> ~60Mbps

Is this the expected behavior for the Ethernet controller on this board?  Is there a patch planned to increase performance?  I am using the Linux BSP LTIB L3.0.35_4.0.0_130424.

[YixingKong]

Steve, please click Correct Answer/Helpful Answer if your question has been answered.

Thanks,

Yixing

[maheshmahadeva1]

I have not tried in 1G network. However below are the results when I run in 100Base-T network:

On the board:

1. iperf -c <server_ip> -i 2 -p 50000 -t 20

root@linaro-ubuntu-desktop:~# iperf -c 10.81.16.146 -i 2 -p 50000 -t 20

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

Client connecting to 10.81.16.146, TCP port 50000

TCP window size: 16.0 KByte (default)

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

[  3] local 10.81.17.25 port 46342 connected with 10.81.16.146 port 50000

[ ID] Interval       Transfer     Bandwidth

[  3]  0.0- 2.0 sec  23.1 MBytes  97.0 Mbits/sec

[  3]  2.0- 4.0 sec  22.4 MBytes  93.8 Mbits/sec

[  3]  4.0- 6.0 sec  22.5 MBytes  94.4 Mbits/sec

[  3]  6.0- 8.0 sec  22.2 MBytes  93.3 Mbits/sec

[  3]  8.0-10.0 sec  22.6 MBytes  94.9 Mbits/sec

[  3] 10.0-12.0 sec  22.4 MBytes  93.8 Mbits/sec

[  3] 12.0-14.0 sec  22.4 MBytes  93.8 Mbits/sec

[  3] 14.0-16.0 sec  22.5 MBytes  94.4 Mbits/sec

[  3] 16.0-18.0 sec  22.5 MBytes  94.4 Mbits/sec

[  3] 18.0-20.0 sec  22.5 MBytes  94.4 Mbits/sec

[  3]  0.0-20.0 sec   225 MBytes  94.4 Mbits/sec

2.

root@linaro-ubuntu-desktop:~# iperf -s -i 2 -p 50000

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

Server listening on TCP port 50000

TCP window size: 85.3 KByte (default)

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

[  4] local 10.81.17.25 port 50000 connected with 10.81.16.146 port 47339

[ ID] Interval       Transfer     Bandwidth

[  4]  0.0- 2.0 sec  22.4 MBytes  94.2 Mbits/sec

[  4]  2.0- 4.0 sec  22.4 MBytes  94.1 Mbits/sec

[  4]  4.0- 6.0 sec  22.4 MBytes  94.2 Mbits/sec

[  4]  6.0- 8.0 sec  22.4 MBytes  94.2 Mbits/sec

[  4]  8.0-10.0 sec  22.4 MBytes  94.1 Mbits/sec

[  4] 10.0-12.0 sec  22.4 MBytes  94.2 Mbits/sec

[  4] 12.0-14.0 sec  22.4 MBytes  94.1 Mbits/sec

[  4] 14.0-16.0 sec  22.4 MBytes  94.1 Mbits/sec

[  4] 16.0-18.0 sec  22.4 MBytes  94.2 Mbits/sec

[  4] 18.0-20.0 sec  22.4 MBytes  94.1 Mbits/sec

[  4]  0.0-20.1 sec   226 MBytes  94.1 Mbits/sec

So I do not see the 60Mbps numbers that is being reported.

I was using the u-boot and uImage that was included in the 4.0.0 release available on freescale.com

Best regards,

-Mahesh

[maheshmahadeva1]

Hi,

What Rev of Silicon are you using (should be printed by U-Boot during platform boot).

Could you try passing 'enable_wait_mode=off' kernel parameter through the U-Boot bootargs variable and re-run your test.

Best regards,

-Mahesh