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 <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? 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 -- 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
