ib_send_bw is script that is part of testperf package (you should have it with the installation of MLNX_OFED).
When using this script, you can test the bandwidth of the link between the servers.
there are similar other script that check latency and throughput.
In general, you need to run server on one host, and the client on another host.
on the server run:
#ib_send_bw -d mlx4_0 -i 1 -F --report_gbits
on the client run
#ib_send_bw -d mlx4_0 -i 1 -F --report_gbits 192.168.100.189
Try running ib_send_bw -h to see additional parameters of this command and some help.
#ib_send_bw -h
More tuning info can be found here:
Thanks,
Ophir