Re: RTL8723BE performance regression

From: Steve deRosier
Date: Wed Apr 04 2018 - 10:55:29 EST

On Tue, Apr 3, 2018 at 6:51 PM, JoÃo Paulo Rechi Vita <jprvita@xxxxxxxxx> wrote:
> This are the results (testing with I got at some key points:
> Version Commit Ping Down Up
> v4.11 a351e9b 12 25.44 5.99
> v4.11 a351e9b 131 17.02 5.89
> v4.13 569dbb8 174 14.08 0.00
> v4.13 569dbb8 261 8.41 0.00
> v4.15+revert d8a5b80 19 23.86 1.41
> v4.15+revert d8a5b80 189 18.69 1.39

I recommend doing throughput testing in a closed system using iperf. is potentially useful for testing your ISP's bandwidth
at some particular point in time, but little else as it exposes you to
too many variables. I wouldn't take those numbers to mean much and the
inconclusive results you're getting could be explained by external
network loading and having little to do with your bisect effort. I can
get that spread in numbers from without making any
changes other than the time of day I do the test.

Here's how to do it. Install iperf2 (you could use iperf3, personal
choice) on two machines, one being your device under test (DUT). Setup
a network configuration that looks similar to this:

server <==hardwire==> AP <--wireless link--> DUT

Be sure your hardwire is more bandwidth than your wireless link is
capable of, or set it up where the server is the AP. What you're
looking for here is environmental consistency, not maximum throughput

On the computer hardwired to the network, start the server, we'll
assume it has an ip of

iperf -s

On your DUT:

iperf -c

That's the most basic setup, check the man page for more options.

You will get best results if you can exclude other computers from your
test network and other wireless devices from your airspace.

- Steve

Steve deRosier
Cal-Sierra Consulting LLC