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Re: APU2 routing speed NetBSD



76nemo76%gmx.ch@localhost writes:

>      I am working with an APU2 board (4gb, 3 lan and AMD CPu 1Ghz
> you can see specifications here http://www.pcengines.ch/apu2.htm)
> to make a router/firewall.
>
> Before choosing the OS I want to use I have done some benchmarks.
> My first benchmark is:
>              1) Copy of a big file (17GB) compressed with gzip
>                 from a Windows 10 machine to a Windows 8.1 machine.
>                 This is done by using CIFS on Windows. Each machine
>                 is at one side of the router.
>
> The results are strange:
>             With OpenBSD and Linux (alpine linux 3.4) I get
>             the maximum speed (112Mbytes/sec) while with NetBSD
>             the speed is limited to 70Mbytes/sec.

There are basically two things to see about.  One is the raw speed of
packet forwarding.  The other is whether there is any loss and how that
interacts with congestion control.  Plus then there are odd things I am
not thinking of.

NetBSD itself should be efficient.  However, you are pushing close to 1
Gb/s.  So, I would want to look at network counters to see if there is
any trouble.  Do "netstat -s" on the router to a file, before and after,
and diff -u.  Also, do the equivalent on the test machines.

This will slow it down, but run tcpudmp and save to a file, and look
over it.  If TCP, use tcpdump2xplot from xplot in pkgsrc (read the docs;
this is not really easy, but very helpful to understand TCP behavior).
If CIFS is over UDP, look at retransmission specs on the clients.

Understand what MTU is being used, with various systems.  Jumbo frames
of 8K data plus header may be faster due to amortizing per-packet
overhead and faster pack/unpack.  THose may be enabled by the others.

Finally, 70 MB/s is still half of GbE, and it may be that other
considerations are more important than the last bit of speed.  But
still, I think this should go faster.

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