Hi Franky,
On Fr, 2016-08-05 at 17:56 -0700, Franky Lin wrote:
> On Fri, Aug 5, 2016 at 2:29 PM, Jörg Krause <[email protected]
> cks>
> wrote:
>
> >
> >
> >
> > Am 5. August 2016 23:01:10 MESZ, schrieb Arend Van Spriel <
> > [email protected]>:
> > >
> > > Op 5 aug. 2016 22:46 schreef "Jörg Krause"
> > > <[email protected]>:
> > > >
> > > >
> > > > Hi,
> > > >
> > > > I'm using a custom ARM board with an BCM43362 wifi chip from
> > > Broadcom.
> > > >
> > > > The wifi chip is attached via SDIO to the controller with a
> > > > clock of
> > > > 48MHz. Linux kernel version is 4.7.
> > > >
> > > > When measuring the network bandwidth with iperf3 I get a
> > > > bandwith of
> > > > only around 5 Mbps. I found a similar thread at the Broadcom
> > > community
> > > >
> > > > [1] where the test was done with a M4 CPU + BCM43362 and an
> > > > average
> > > > result of 3.3 Mbps.
> > > >
> > > > Interestingly, a BCM43362 Wi-Fi Dev Kit [2] notes a TCP data
> > > throughput
> > > >
> > > > greater than 20 Mbps.
> > > >
> > > > Why is the throughput I measured much lower? Note that I
> > > > measured
> > > > several times with almost no neighbor devices or networks.
> > > >
> > > > This is a test sample measured with iperf3:
> > > >
> > > > $ iperf3 -c 192.168.2.1 -i 1 -t 10
> > > > Connecting to host 192.168.2.1, port 5201
> > > > [ 4] local 192.168.2.155 port 36442 connected to
> > > > 192.168.2.1
> > > port
> > > >
> > > > 5201
> > > > [ ID]
> > > > Interval Transfer Bandwidth Retr Cwnd
> > > > [ 4] 0.00-1.00 sec 615 KBytes 5.04
> > > > Mbits/sec 0 56.6
> > > > KBytes
> > > > [ 4] 1.00-2.00 sec 622 KBytes 5.10
> > > > Mbits/sec 0 84.8
> > > > KBytes
> > > > [ 4] 2.00-3.00 sec 625 KBytes 5.12
> > > > Mbits/sec 0 113
> > > > KBytes
> > > > [ 4] 3.00-4.00 sec 571 KBytes 4.68
> > > > Mbits/sec 0 140
> > > > KBytes
> > > > [ 4] 4.00-5.00 sec 594 KBytes 4.87
> > > > Mbits/sec 0 167
> > > > KBytes
> > > > [ 4] 5.00-6.00 sec 628 KBytes 5.14
> > > > Mbits/sec 0 195
> > > > KBytes
> > > > [ 4] 6.00-7.00 sec 619 KBytes 5.07
> > > > Mbits/sec 0 202
> > > > KBytes
> > > > [ 4] 7.00-8.00 sec 608 KBytes 4.98
> > > > Mbits/sec 0 202
> > > > KBytes
> > > > [ 4] 8.00-9.00 sec 602 KBytes 4.93
> > > > Mbits/sec 0 202
> > > > KBytes
> > > > [ 4] 9.00-10.00 sec 537 KBytes 4.40
> > > > Mbits/sec 0 202
> > > > KBytes
> > > > - - - - - - - - - - - - - - - - - - - - - - - - -
> > > > [ ID] Interval Transfer Bandwidth Retr
> > > > [ 4] 0.00-10.00 sec 5.88 MBytes 4.93
> > > > Mbits/sec 0 sender
> > > > [ 4] 0.00-10.00 sec 5.68 MBytes 4.76
> > > > Mbits/sec receiver
> > >
> > > Not overly familiar with iperf3. Do these lines mean you are
> > > doing
> > > bidirectional test, ie. upstream and downstream at the same time.
> > > Another
> > > thing affecting tput could be power-save.
> >
> > No, iperf3 does not support bidrectional test. Power-save is turned
> > off.
> >
> > What does iw link say?
It says:
# iw dev wlan0 link
Connected to xx:xx:xx:xx:xx (on wlan0)
SSID: xxx
freq: 2437
signal: -60 dBm
tx bitrate: 58.5 MBit/s
bss flags: short-preamble short-slot-time
dtim period: 1
beacon int: 100
Best regards
Jörg Krause