User Manual

Rev 4.60
Mellanox Technologies
107
8.4.6.1 ib_write_lat Synopsys
8.4.6.2 ib_write_lat Options
The table below lists the various flags of the command.
8.4.7 ibv_read_bw
This is a more advanced version of ib_read_bw and contains more flags and features than the
older version and also improved algorithms. ibv_read_bw calculates the BW of RDMA read
between a pair of machines. One acts as a server, and the other as a client. The client RDMA
reads the server memory and calculate the BW by sampling the CPU each time it receive a suc-
cessful completion. The test supports a large variety of features as described below, and has bet-
ter performance than ib_read_bw in Nahalem systems. Read is available only in RC connection
mode (as specified in the InfiniBand spec).
ib_write_lat [-i(b_port) ib_port] [-c(onnection_type) RC\UC] [-m(tu) mtu_size] [-
s(ize) message_size] [-t(x-depth) tx_size] [-n iteration_num] [-p(ort)
PDT_port] [-a(ll)] [-V(ersion)] [-C report cycles] [-H
report histogram] [-U report unsorted]
Table 37 - ib_write_lat Flags and Options
Flag Description
-p, --port=<port> Listens on/connect to port <port> (default 18515)
-d, --ib-dev=<dev> Uses IB device <device guid> (default first device found)
-i, --ib-port=<port> Uses port <port> of IB device (default 1)
-m, --mtu=<mtu> The mtu size (default 1024)
-c, --connection=<RC/UC> Connection type RC/UC (default RC)
-s, --size=<size> The size of message to exchange (default 65536)
-f, --freq=<dep> How often the time stamp is taken
-a, --all Runs sizes from 2 till 2^23
-t, --tx-depth=<dep> The size of tx queue (default 100)
-n, --iters=<iters> The number of exchanges (at least 2, default 1000)
-C, --report-cycles Reports times in cpu cycle units (default microseconds)
-H, --report-histogram Prints out all results (default print summary only)
-U, --report-unsorted (implies -
H)
Prints out unsorted results (default sorted)
-V, --version Displays version number
-g, --grh Uses GRH with packets (mandatory for RoCE)