Return-path: Received: from mail-gx0-f13.google.com ([209.85.217.13]:48709 "EHLO mail-gx0-f13.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752189AbYLTHmR (ORCPT ); Sat, 20 Dec 2008 02:42:17 -0500 Received: by gxk6 with SMTP id 6so1239885gxk.13 for ; Fri, 19 Dec 2008 23:42:16 -0800 (PST) Message-ID: (sfid-20081220_084313_775250_C9FBA21C) Date: Fri, 19 Dec 2008 23:42:16 -0800 From: "Daniel Wu" To: linux-wireless@vger.kernel.org Subject: iwlagn and Intel 5300 card mimo3 poor performance? MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, We are running into some unexpected results in performance tests of an Intel 5300 abgn against a Linksys wrt310n. Any help would be greatly appreciated. Using the debugfs and writing a fixed rate hex into the rate_scale_table, we tested the throughput (with iperf UDP mode) between the Intel 5300 card to another wired laptop through the wrt310n. As far as we can tell, legacy cck, ofdm and siso performance are fine. We're running into problems when trying to set up triple streams and three antennas (mimo3). We're using these hex rates for mimo3: 0x1C110 0x1C111 0x1C112 0x1C113 0x1C114 0x1C115 0x1C116 0x1C117 For each of the rates, we're getting approximately 160Kbps which is far too low. These rates also seem to cause a "Invalid HT rate index 236" in dmesg. At first we thought the 5300 may not be able to do 3 streams at once, but that's not true, since the device can receive from the AP at much higher rates (~64.5Mbps) Also, in iwl-commands.h, there might be a typo on line 258, instead of bits "3-0", it should be at least bits "6-0"