Somewhat improved iperf3 performance on Chelsio T6225-CR

After upgrading to stable/11, r339418, incorporating the recent commits for cxgbe(4) et al. (r339389, and r339393-r339404), I see a somewhat improved iperf3 performance.

Previously, I saw terrible performance down into the 3 Mbit/s range when transmitting, but not when receiving. The remote host has only a 1 Gbit/s connection, whereas the local host has a 10 Gbit/s connection. Still, I see non-zero counts for the retries, which indicates a problem.

$ iperf3 -6NRc remote-host
Connecting to host remote-host, port 5201
Reverse mode, remote host remote-host is sending
[  5] local 2001:db8:1:1::2 port 32736 connected to 2001:db8:1:1::3 port 5201
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   104 MBytes   873 Mbits/sec
[  5]   1.00-2.00   sec   111 MBytes   928 Mbits/sec
[  5]   2.00-3.00   sec   111 MBytes   928 Mbits/sec
[  5]   3.00-4.00   sec   111 MBytes   928 Mbits/sec
[  5]   4.00-5.00   sec   111 MBytes   928 Mbits/sec
[  5]   5.00-6.00   sec   111 MBytes   928 Mbits/sec
[  5]   6.00-7.00   sec   111 MBytes   928 Mbits/sec
[  5]   7.00-8.00   sec   111 MBytes   927 Mbits/sec
[  5]   8.00-9.00   sec   111 MBytes   928 Mbits/sec
[  5]   9.00-10.00  sec   111 MBytes   928 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.05  sec  1.08 GBytes   920 Mbits/sec  1063             sender
[  5]   0.00-10.00  sec  1.07 GBytes   922 Mbits/sec                  receiver

iperf Done.

$ iperf3 -6Nc remote-host
Connecting to host remote-host, port 5201
[  5] local 2001:db8:1:1::2 port 32741 connected to 2001:db8:1:1::3 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   109 MBytes   916 Mbits/sec    0   3.06 MBytes
[  5]   1.00-2.00   sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
[  5]   2.00-3.00   sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
[  5]   3.00-4.00   sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
[  5]   4.00-5.00   sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
[  5]   5.00-6.00   sec   111 MBytes   928 Mbits/sec    0   3.06 MBytes
[  5]   6.00-7.00   sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
[  5]   7.00-8.00   sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
[  5]   8.00-9.00   sec   111 MBytes   928 Mbits/sec    0   3.06 MBytes
[  5]   9.00-10.00  sec   111 MBytes   929 Mbits/sec    0   3.06 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.08 GBytes   927 Mbits/sec    0             sender
[  5]   0.00-10.09  sec  1.08 GBytes   919 Mbits/sec                  receiver

iperf Done.

$ iperf3 -4NRc remote-host
Connecting to host remote-host, port 5201
Reverse mode, remote host remote-host is sending
[  5] local 192.0.2.2 port 38274 connected to 192.0.2.3 port 5201
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  63.4 MBytes   532 Mbits/sec
[  5]   1.00-2.00   sec   112 MBytes   941 Mbits/sec
[  5]   2.00-3.00   sec   112 MBytes   941 Mbits/sec
[  5]   3.00-4.00   sec   112 MBytes   941 Mbits/sec
[  5]   4.00-5.00   sec   111 MBytes   933 Mbits/sec
[  5]   5.00-6.00   sec   112 MBytes   941 Mbits/sec
[  5]   6.00-7.00   sec   109 MBytes   916 Mbits/sec
[  5]   7.00-8.00   sec  56.4 MBytes   472 Mbits/sec
[  5]   8.00-9.00   sec   101 MBytes   849 Mbits/sec
[  5]   9.00-10.00  sec   112 MBytes   941 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.13  sec  1005 MBytes   833 Mbits/sec  402             sender
[  5]   0.00-10.00  sec  1003 MBytes   841 Mbits/sec                  receiver

iperf Done.

$ iperf3 -4Nc remote-host
Connecting to host remote-host, port 5201
[  5] local 192.0.2.2 port 38281 connected to 192.0.2.3 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   113 MBytes   951 Mbits/sec    0   4.06 MBytes
[  5]   1.00-2.00   sec   109 MBytes   915 Mbits/sec    0   4.06 MBytes
[  5]   2.00-3.00   sec   104 MBytes   870 Mbits/sec  4044    616 KBytes
[  5]   3.00-4.00   sec   112 MBytes   942 Mbits/sec    0    908 KBytes
[  5]   4.00-5.00   sec   112 MBytes   942 Mbits/sec    0   1.82 MBytes
[  5]   5.00-6.00   sec   112 MBytes   942 Mbits/sec    0   2.94 MBytes
[  5]   6.00-7.09   sec  96.4 MBytes   740 Mbits/sec    0   4.00 MBytes
[  5]   7.09-8.00   sec   103 MBytes   955 Mbits/sec  3142   2.20 MBytes
[  5]   8.00-9.00   sec   112 MBytes   942 Mbits/sec    0   2.36 MBytes
[  5]   9.00-10.00  sec   112 MBytes   942 Mbits/sec    0   2.96 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.06 GBytes   912 Mbits/sec  7186             sender
[  5]   0.00-10.09  sec  1.06 GBytes   901 Mbits/sec                  receiver

iperf Done.

#notsponsored

Published by

Trond Endrestøl

I stopped counting my age years ago. Personal interests besides computers and computer networks include, but are not limited to, astronomy, comics, music, and science (fiction).

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