One both machines run:

sudo apt-get install iperf

Then on Computer A:

iperf -s

And on Computer B:

iperf -c <address of Computer A>

On the client machine, you’ll see something like this:

oli@bert:~$ iperf -c tim
------------------------------------------------------------
Client connecting to tim, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 192.168.0.4 port 37248 connected with 192.168.0.5 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.04 GBytes    893 Mbits/sec

参考: How do you test the network speed betwen two boxes?