Hi all, On Fr, 2016-08-05 at 17:56 -0700, Franky Lin wrote: On Fri, Aug 5, 2016 at 2:29 PM, Jörg Krause <joerg.krause@xxxxxxxxxxx cks> wrote: Am 5. August 2016 23:01:10 MESZ, schrieb Arend Van Spriel < arend.vanspriel@xxxxxxxxxxxx>: Op 5 aug. 2016 22:46 schreef "Jörg Krause" <joerg.krause@embedded.rocks>: 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? I compared the results with a Cubietruck I have: # iperf3 -s ----------------------------------------------------------- Server listening on 5201 ----------------------------------------------------------- Accepted connection from 192.168.178.46, port 42906 [ 5] local 192.168.178.38 port 5201 connected to 192.168.178.46 port 42908 [ ID] Interval Transfer Bandwidth [ 5] 0.00-1.00 sec 2.29 MBytes 19.2 Mbits/sec [ 5] 1.00-2.00 sec 2.21 MBytes 18.5 Mbits/sec [ 5] 2.00-3.00 sec 2.17 MBytes 18.2 Mbits/sec [ 5] 3.00-4.00 sec 2.09 MBytes 17.6 Mbits/sec [ 5] 4.00-5.00 sec 2.20 MBytes 18.5 Mbits/sec [ 5] 5.00-6.00 sec 2.64 MBytes 22.1 Mbits/sec [ 5] 6.00-7.00 sec 2.67 MBytes 22.4 Mbits/sec [ 5] 7.00-8.00 sec 2.62 MBytes 22.0 Mbits/sec [ 5] 8.00-9.00 sec 2.35 MBytes 19.8 Mbits/sec [ 5] 9.00-10.00 sec 2.30 MBytes 19.3 Mbits/sec [ 5] 10.00-10.03 sec 83.4 KBytes 23.5 Mbits/sec - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Retr [ 5] 0.00-10.03 sec 23.9 MBytes 20.0 Mbits/sec 0 sender [ 5] 0.00-10.03 sec 23.6 MBytes 19.8 Mbits/sec receiver # iw dev wlan0 link Connected to xx:xx:xx:xx:xx (on wlan0) SSID: xxx freq: 2437 tx bitrate: 65.0 MBit/s bss flags: short-preamble short-slot-time dtim period: 1 beacon int: 100 The Cubietruck works also with the brcmfmac driver. May it depend on the NVRAM file? Best regards Jörg Krause -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
