BeagleBone slow inbound net I/O

[Tom Pusateri]

> On Mar 13, 2015, at 8:34 AM, Paul Mather <paul at gromit.dlib.vt.edu> wrote:
> 
> On Mar 12, 2015, at 11:26 PM, Brett Wynkoop <freebsd-arm at wynn.com> wrote:
> 
>> Greeting-
>> 
>> It is confirmed, the net I/O is much slower than reading from the SD
>> card.  Here is another run of tar - pipe - tar, but this time the
>> source is the sd card and the destination is still the USB zfs.
> 
> 
> The Beaglebone uses a USB NIC so any I/O to/from SD card will be competing for resources and potentially slowing things down.
> 
> Have you tried outputting to /dev/null to get a more accurate sense of how performant the network I/O alone is?  Alternatively, how about using something like benchmarks/netperf?


benchmarks/iperf is a good one too. It will figure out the maximum bandwidth you can sustain. It's available on Linux and Mac OSX too for the other end of the test.

# run this on one side of the connection and it will start listening as a server:
% iperf -s

# on the client side, pick an IP address on the server
% iperf -c <ip address of server>

There's a pretty nice article here about other features of iperf too:

http://crok-linkblog.homelinux.com/links-cisco/how-to-use-iperf-properly-additions-to-the-tcp-throughput-post/


Tom
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