Bob, real world work interfered back in June but now I have a few more data points. I made a cross test with ath5k on Fedora 2.6.40 (e.g. 3.0) and Madwifi-0.9.4 on 2.6.23. The interesting observation is, that the ath5k bottleneck seems to be on the transmission end, e.g if the iperf client is attached to ath5k, the performance is consistently lower. Here is a table: ath5k-ath5k = iperf server attached to ath5k, iperf client attached to ath5k madwifi-ath5k = iperf server attached to madwifi, iperf client attached to ath5k ath5k-madwifi = iperf server attached to ath5k, iperf client attached to madwifi madwifi-madwifi = iperf server attached to madwifi, iperf client attached to madwifi Note that on iperf the server is the traffic sink (and the measurement point) and the client is the traffic source. Measured traffic was UDP as generated by iperf -c <ip of server> -u -b 54M -t 15 The test setup was as followed: * 59db attenuation between the two boxes (calibrated HF cable) * Frequency 5200MHz (eg. 802.11a channel 40) * txpower 10dBm on both sides * ANI disabled on Madwifi *SLOW* *SLOW* *FAST* *FAST* ath5k-ath5k madwifi-ath5k ath5k-madwifi madwifi-madwifi 27553680 27553680 7426440 33998160 28082880 28135800 24866520 33851160 28212240 28212240 32281200 33615960 28323960 28112280 33033840 34027560 28300440 28259280 32363520 34303920 28088760 28276920 34739040 34021680 28112280 28212240 34874280 34415640 28247520 28088760 34298040 33886440 28247520 28235760 34004040 34292160 28176960 28141680 34944840 34409760 27930000 28224000 35015400 34174560 28206360 28159320 35085960 34403880 28135800 28082880 33574800 33951120 28135800 28041720 34986000 34045200 28147560 27965280 35133000 34174560 I will run with tcpdump on a monitoring interface for the combination ath5k sender and madwifi sender shortly. Where should I capture the trace? -- Regards Joerg ----- Ursprüngliche Message ----- > Von: Bob Copeland <me@xxxxxxxxxxxxxxx> > An: Joerg Pommnitz <pommnitz@xxxxxxxxx> > Cc: linux-wireless@xxxxxxxxxxxxxxx; ath5k-devel@xxxxxxxxxxxxxxx > Gesendet: 13:02 Donnerstag, 30.Juni 2011 > Betreff: Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211 > > On Wed, Jun 22, 2011 at 11:07 AM, Joerg Pommnitz <pommnitz@xxxxxxxxx> > wrote: >>> I guess you'll need more help from the HW people here. >> >> Bob, Bruno, Felix, Luis, Nick: Do you read? > > I guess I would be interested to know if there are any obvious > differences in the streams. E.g. taking a monitor mode capture > near the receiver should show whether the received power is similar, > whether the # of retransmissions is significantly higher in ath5k > vs madwifi, whether packets are sent at the same bitrates, if there > are any pauses where ath5k doesn't seem to be doing anything, etc. > > Would it be possible to do a few captures with your setup? > -- > Bob Copeland %% www.bobcopeland.com > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
