Dear Developers, during the last weeks i've been experimenting with multiple AR9x Atheros cards driven by ath9k. I did some 802.11n throuput tests with an Ubiquiti SR-71-12 (AR9220-AC1E) and Unex DNMA-H5 (AR9160-BC1B) in an Alix 3D Geode Board and another Ubiquiti SR-71 (AR9220) in an Acer Dual-Core Atom Netbook. I've been using linux-next checked out on Friday, 06.09.2010 for all my tests.
First, I measured the performance against the cards themselves. I always got around 90mbit/s, HT20 AND HT40. Then, i connected to an Apple (don't know which card), Win7 Intel 5100, and a D-Link DIR-825 Router (AR9220, Atheros Blob). The results always were just the same: Sending rate towards these devices was always around 20mbit/s, MCS varying from 3 to 5, receiving around 90mbit/s. I did all my tests in the same room. There was another network at g band, but not a. But results were the same. Using adhoc, AP or station with iw or wpa_supplicant also made no differences. To exclude environmental influences, i connected the Atheros cards to the D- Link by wire. ath9k was sending with full MCS15 SGI, 240mbit/s from the netbook, 220mbit/s from the Alix board (iperf UDP). Looks fine. I tried ath9k_rate_control and minstrel_ht with the same results. Are there problems with signal quality calculation or what forces the rate algorithms to choose such a low bitrate? Rx still didn't exceed those 90mbit/s. As the Netbook operated at the same rate, I think I can exclude CPU problems. There must be some reason limiting the overall transfer rate to ~90mbit/s! Examining debugfs a little, i can see there are no rx drops nor lost interrupts. Does anyone have a hint what this could be related to? Where should i start investigating? I have experience with driver programming, but ath9k and mac80211 are still pretty new to me. Thanks in Advance, Alex _______________________________________________ ath9k-devel mailing list [email protected] https://lists.ath9k.org/mailman/listinfo/ath9k-devel
