Measure pipe throughput in the shell

cpipe is probably better for these purposes, but another related program is pv (Pipe Viewer):

If you give it the --rate flag it will show the transfer rate

You need a utility called cpipe.

Usage:

tar cCf / - usr | cpipe -vr -vw -vt > /dev/null

Output:

...
  in:  19.541ms at    6.4MB/s (   4.7MB/s avg)    2.0MB
 out:   0.004ms at   30.5GB/s (  27.1GB/s avg)    2.0MB
thru:  19.865ms at    6.3MB/s (   4.6MB/s avg)    2.0MB
...