Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933443Ab0HNIxd (ORCPT ); Sat, 14 Aug 2010 04:53:33 -0400 Received: from mx0.vr-web.de ([195.200.35.198]:39825 "EHLO mx0.vr-web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932985Ab0HNIxc (ORCPT ); Sat, 14 Aug 2010 04:53:32 -0400 From: Andreas X-Newsgroups: linux.kernel Subject: Re: rt61pci - bad performance Date: Sat, 14 Aug 2010 10:55:17 +0200 Organization: privat Message-ID: <4C6659F5.9080706@01019freenet.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@arcor.de To: Helmut Schaa User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; de; rv:1.9.3a6pre) Gecko/20100803 SeaMonkey/2.1a2 In-Reply-To: To: linux-kernel@vger.kernel.org X-BitDefender-Scanner: Clean, Agent: BitDefender Courier 3.0.2 on vrwf103, sigver: 7.28621 X-BitDefender-CF-Stamp: none Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5006 Lines: 147 Helmut Schaa wrote: > Hi Andreas, > > Am Freitag 13 August 2010 schrieb Andrew Morton: >> (cc's added) >> >> On Sun, 08 Aug 2010 11:49:49 +0200 >> Andreas wrote: > > [...] > >>> wlan0 IEEE 802.11bg ESSID:"--------" >>> Mode:Managed Frequency:2.412 GHz Access Point: some AP >>> Bit Rate=1 Mb/s Tx-Power=5 dBm >>> Retry long limit:7 RTS thr:off Fragment thr:off >>> Encryption key:off >>> Power Management:off >>> Link Quality=38/70 Signal level=-72 dBm >>> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 >>> Tx excessive retries:0 Invalid misc:0 Missed beacon:0 >>> >>> The throughput is measured with ping -f -s 7000 and xosview -n. > > This doesn't look like an appropriate way to measure the throughput. You > should use something like iperf [1] or netperf [2] for your measurements > to get more accurate results. > >>> If I'm using ndiswrapper with the windows driver, first of all, I can >>> see additional information in iwconfig: >>> >>> wlan0 IEEE 802.11g ESSID:"--------" >>> Mode:Managed Frequency:2.412 GHz Access Point: some AP >>> Bit Rate=54 Mb/s Tx-Power:20 dBm Sensitivity=-121 dBm >>> RTS thr=2347 B Fragment thr=2346 B >>> Encryption key:some key Security mode:restricted >>> Power Management:off >>> Link Quality:62/100 Signal level:-56 dBm Noise level:-96 dBm >>> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 >>> Tx excessive retries:0 Invalid misc:0 Missed beacon:0 >>> >>> >>> There is a switch for sensitivity (which is not supported with rt61pci) >>> and the link quality compared with ndiswrapper is worse (38% to 62%). > > I wouldn't trust the link quality values that much, the calculation in rt61pi > is most likely different from what the windows driver does. So it is not > really comparable. I detected the problem using tunneled ssh-x-sessions and during copying of data. I'm not really interested in the link-quality - I just need a high performance :-). >>> The following is remarkably too: >>> ndiswrapper uses a Tx-Power of 20 dBm, rt61pci only 5 dBm. I don't know, >>> why rt61pci uses 5 dBm. It's a hard limit and I can't set it on a value >>> higher than 5 unless the driver is patched. Nevertheless, setting a >>> higher value (of 20 dBm) by patch does not mean to get a better performance. > > Could you elaborate please? Did you actually try to patch it or is this just > an assumption? see my other mail! >>> Ndiswrapper shows an encryption key, rt61pci not. Does it mean, that >>> rt61pci doesn't use hardware encryption? > > hw crypto should be enabled by default in rt61pci, however, I don't know > if it is actually working ;) How can I see if it's working? >>> With ndiswrapper, the rt61pci-chip achieves a throughput of 2,6 MBytes/s >>> - that's about 1 MByte/s more than rt61pci. >>> >>> I have to say, that the difference between rt61pci and ndiswrapper gets >>> worse if the link quality is getting more badly. Or in other words: >>> ndiswrapper handles bad connections better then rt61pci. >>> >>> >>> Do you have any idea to get rt61pci working as fast as ndiswrapper? > > Please run proper measurements first and post the results again. I did some measurements with netperf (TCP_STREAM): ndiswrapper =========== (OpenSuSE 11.2 2.6.31.13-21): download average min max 20,88 19,02 22,19 MBit/s (6 runs) upstream average min max 21,46 18,84 22,26 MBits/s (7 runs) OpenSuSE 11.3 (2.6.34-12-desktop) download average min max 21,41 20,51 22,51 MBit/s (16 runs) upstream average min max error rt61pci (patched - compat-wireless-2010-07-20) ============================================== OpenSuSE 11.3 (2.6.34-12-desktop) download average min max 15,54 12,4 17,19 MBit/s (25 runs) upstream average min max 13,54 12,1 14,04 MBits/s (7 runs) rt61pci (original (unpatched) from OpenSuSE 11.3) ============================================== download 0,7 MBit/s upstream error (interrupted system call) If you compare ndiswrapper with rt61pci patched, there is a difference of about 6 MBits/s. The unpatched version can't be used at all. Another point is the upstream issue with ndiswrapper with 2.6.34-kernels, which appears under some conditions (under "normal" conditions, I didn't see this problem yet). Do you need some special tests? Please ask for them - I'll try to provide them! Thanks for you help, kind regards, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/