Subject: Re: multiple wireless cards
Newsgroups: gmane.linux.drivers.madwifi.devel
Date: 2008-07-20 08:12:10 GMT (24 weeks, 5 days, 19 hours and 46 minutes ago)
Hi, there is another issue, that may cause your throughput reduction. The soekris board might not be powerfull enough for two flows at 54M. We have had similar issues with soekris boards (i can't remember whether they were 4801 or another type from the top of my head). And it was clearly due to cpu-limitations. Try monitoring your cpu-usage during the transmissions - "top" will show you the system-usage. Nonetheless, since you are using high-power adapter, crosstalk is also very likely. Regards, Moritz Grauel Am 19.07.2008 um 21:24 schrieb emilio ancillotti: > Hi there, > > I have a problem using 2 Atheros based wireless cards at the same > time. > Secifically, when each card works alone the driver works fine. > However, > when both cards work simultaneously, the per flow throughput of each > cards is reduce of about 30-40%, even if the two wireless cards use > different channels (1 and 11). > My testbed consisted of a soekris 4801 with 2 R52H High Power Mikrotik > 802.11a/b/g mPCI adapter runnig the madwifi 0.9.4 and the linux kernel > 2.6.22. > To see the throughput reduction I opened two outgoing asimptotic UDP > flows (using the iperf tool) between the soekris board and two laptop. > The two wireless cards worked in ad-hoc mode and I used 54Mbps as the > wireless transmission rate (I disable the autorate alghoritm). > > Has anyone experienced the same problem? > > I would be really grateful if anyone shared his experience relative to > my question. > > Regards, > Emilio Ancillotti > > ---------------------------------------------------------------------- > --- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > Build the coolest Linux based applications with Moblin SDK & win > great prizes > Grand prize is a trip for two to an Open Source event anywhere in > the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Madwifi-devel mailing list > Madwifi-devel <at> lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/madwifi-devel ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/