Return-path: Received: from mout02.posteo.de ([185.67.36.142]:60737 "EHLO mout02.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2998826AbcHEU52 (ORCPT ); Fri, 5 Aug 2016 16:57:28 -0400 Message-ID: <1470429980.29489.10.camel@embedded.rocks> (sfid-20160805_225811_086669_94AF5D07) Subject: TCP data throughput for BCM43362 From: =?ISO-8859-1?Q?J=F6rg?= Krause To: linux-wireless@vger.kernel.org Cc: brcm80211-dev-list , Brett Rudley , Arend van Spriel , Franky Lin , Hante Meuleman Date: Fri, 05 Aug 2016 22:46:20 +0200 Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 [1] https://community.broadcom.com/thread/3978 [2] http://www.mouser.de/new/broadcom/broadcom-bcm943362wcd4/ Best regards Jörg Krause