Re: Raspberry Pi 3B and pitiful network speeds

From: Denis Ovsienko <denis_at_ovsienko.info>
Date: Sun, 20 Jun 2021 22:29:22 +0100
On Sun, 20 Jun 2021 15:41:05 +0100
Denis Ovsienko <denis_at_ovsienko.info> wrote:

> Notwithstanding your point, under right conditions NetBSD 9.2 can
> fully utilize the RPI3B's 100Mbit/s Ethernet interface, at least in
> one direction at a time. Hopefully that means it should be possible in
> FreeBSD too.

As it turns out, it is indeed possible with FreeBSD.

In mostly-simplex tests the RPI3B managed to download at 11.4MB/s or
to upload at 10.2MB/s. A simultaneous two-way test resulted in 7.6MB/s
download and 7.0MB/s upload, so it looks like the 100Mb/s duplex PHY
internally connects through a 150Mb/s simplex bottleneck or some such.
The numbers come from a quick nc+dd test using 1000MB of pseudo-random
data, but I remember observing similar results with iperf earlier
(cannot remember which OS).

The tests were done using FreeBSD 13.0-RELEASE [1] and RPI3B rev A22082
with proper power and cooling. The SD card was a basic one. dd was
reading from /dev/urandom and writing to /dev/null.

As a separate note, in my setup ifconfig tells "100baseTX
<full-duplex>", which is expected for RPI3B. In the original message it
tells "1000baseT <full-duplex>", which means the board is RPI3B+ or
RPI4B. So another useful thing to do in addition to the method above
would be to identify the model exactly and to double-check the earlier
test results (Mb/s or MB/s).

Hopefully this helps to troubleshoot the issue, whatever it is.

1:
https://download.freebsd.org/ftp/releases/arm64/aarch64/ISO-IMAGES/13.0/FreeBSD-13.0-RELEASE-arm64-aarch64-RPI.img.xz

-- 
    Denis Ovsienko
Received on Sun Jun 20 2021 - 21:29:22 UTC

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