Experimenting with network topology and throughput.

[agent_kith]

I am running a new router in my home now. A Celeron 3865U mini PC with 6 ports. I'm not sure if a Celeron is capable of switching gigabit speeds, so tested it out with the iPerf benchmark tool.

So what iperf is doing is really testing the maximum transfer speed (upload or download) of your network. You need a computer running iPerf in server mode (in my case the router), and then run clients at various computers to test the speed.

This is the results of running iPerf in one of the development machines.

Code:

Client connecting to 10.x.x.x, TCP port 5001
TCP window size:  325 KByte (default)
------------------------------------------------------------
[  3] local 10.x.x.x port 42884 connected with 10.x.x.x port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.15 GBytes   987 Mbits/sec

987 Mbits, not too bad. Good to know I'm wrong. Celeron is capable of maxing out a gigabit network.

Next, I try this from my NAS.

Code:

[  3] local 10.x.x.x port 33607 connected with 10.x.x.x port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1014 MBytes   851 Mbits/sec

Not as quick, but still acceptable. Kind of expected because this NAS is running on HP N54L, and I believe it's using Marvel  NIC. This network card is slower than Intel (and consume more power).

And this is the throughput from my primary music player (running Snakeoil of course):

Code:

[  3] local 10.x.x.x port 58196 connected with 10.x.x.x port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   625 MBytes   524 Mbits/sec

524 Mbit/s. This is expected because I am using a PCI network card, PCI maxes out at 533 Mbit/s. So I'm already very close to the limit. Besides USB is 480 Mbits/s so this is OK.

Finally, I run this on the Raspberry Pi 3... And what an appaling result!!

Code:

[  3] local 10.x.x.x port 35116 connected with 10.x.x.x port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   338 MBytes   284 Mbits/sec

284 Mbits/s! Did I got that right?

A quick google couldn't tell me anything conclusive. But it does appear network is a bottle neck with these Pis. As good as they are, there are restrictions when it's a SoC.

USB 2.0 max out at 480 Mbits/s  anyway, so I reckon even at this speed the Pi should be able to handle high res or DSD relatively well. But there's not much room for error here.

ODroids, Banana Pis can sustain higher throughputs. They are also more expensive.

Anyway, why the new router? I am finally going to bite the bullet and seggerate everything in my network into it's own VLAN. Not entirely sure what that'd do, so watch this space.