From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mtiwmhc13.worldnet.att.net ([204.127.131.117]:58634 "EHLO mtiwmhc13.worldnet.att.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757300AbYGZVLF (ORCPT ); Sat, 26 Jul 2008 17:11:05 -0400 Message-ID: <488B92E3.6050200@lwfinger.net> (sfid-20080726_231109_579067_2E010AEA) Date: Sat, 26 Jul 2008 16:10:59 -0500 From: Larry Finger MIME-Version: 1.0 To: =?UTF-8?B?Q8OpZHJpYyBBdWdlcg==?= CC: linux-wireless@vger.kernel.org Subject: Re: iwl3945 slow for downloading References: <20080726161140.59041730@grisbi.org> <488B3969.4050405@openwrt.org> <488B48C1.6090506@lwfinger.net> <20080726183237.02a1e28e@grisbi.org> In-Reply-To: <20080726183237.02a1e28e@grisbi.org> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: C=C3=A9dric Auger wrote: > Le Sat, 26 Jul 2008 10:54:41 -0500, > Larry Finger a =C3=A9crit : >=20 >> Felix Fietkau wrote: >>> I don't know if it helps with debugging this issue, but I've seen >>> the same on a laptop from a friend of mine (same card). >>> >>> After some searching I found that setting the AP to g-only mode >>> instead of b+g mixed made it work at decent speeds. Another symptom >>> of this slowdown is that there is typically an unnaturally high >>> number of retransmissions on the air, which eats up a lot of >>> airtime. >>> >>> I've spent some time looking through the code to find the reason >>> for this but couldn't find anything yet (maybe somebody from Intel >>> could help). >> Just for comparison, my BCM4312 running b43 from the latest >> wireless-testing gets the following tcpperf throughput: >> >> AP Mode TX RX >> >> Mixed b/g 19.8 MB/s 23.0 MB/s >> g-only 20.5 MB/s 23.1 MB/s >> >> For these tests, the connecting end was wired to the router. The >> difference in TX speeds was about what I expected - the small >> difference in RX speeds was not. In any case, if you see a large >> difference with iwl3945, that would be useful information. >> >> You can obtain tcpperf from >> http://wand.cs.waikato.ac.nz/~stj2/nsc/software.html >=20 > hello > thanks for your answers. > i tried to set my ap to g-only, but i cannot :-( the wifi box is give= n > by my provider and it seems cannot be changed... > so i tried tcpperf, this is the result : >=20 > cedric:/home/grisbi/tcpperf-1.754# ./tcpperf -c 192.168.0.4 -t 30 > Duration: 30 9482usec > Bytes sent: 5481472 (5353 kB 5 MB 0 GB) > Bandwidth: 1461264 b/s (1461.26 kb/s 1.46 Mb/s) > Close duration: 0s 22usec >=20 > then i tried to download an image of ubuntu and i had about 900kb/s, > so very good and i don't understand... then i tried to send a big fi= le > with scp to the other computer, as user and as root, it begins at > 2,2MB/s and decrease untill 150kb/s and stays between 130-200kb/s > i did again a tcpperf with -t 300 to check if it's not with the time, > but i have 1,30MB/s, seems correct. >=20 > second test : > i stop the wifi and plug a cable. the second computer is still in wif= i. > tcpperf gives me 17Mb/s and the same file with scp is sent with about > 2,2MB/s... > so now i really don't understand, from internet, loading work untill > 900kb/s (ok for me), but beween 2 computers on my network i have max > 200kb/s... > hopes this can be usefull It looks as if your receive rate is a lot higher than the transmit rate= =2E You can=20 check that by using the computer with the iwl3945 as the server and ini= tiate=20 tcpperf from the other end. Larry -- To unsubscribe from this list: send the line "unsubscribe linux-wireles= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html