Return-path: Received: from mail-ia0-f174.google.com ([209.85.210.174]:61381 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754233Ab3BZSG6 (ORCPT ); Tue, 26 Feb 2013 13:06:58 -0500 Received: by mail-ia0-f174.google.com with SMTP id u20so3649425iag.5 for ; Tue, 26 Feb 2013 10:06:58 -0800 (PST) Message-ID: <512CF9BF.8020302@lwfinger.net> (sfid-20130226_190703_624082_10648503) Date: Tue, 26 Feb 2013 12:06:55 -0600 From: Larry Finger MIME-Version: 1.0 To: Juan Carlos Garza Fernandez CC: linux-wireless@vger.kernel.org Subject: Re: Performance of Ralink 3072 USB Sticks 300Mbit References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 02/26/2013 10:15 AM, Juan Carlos Garza Fernandez wrote: > Hi all, > > I am evaluating the performance of some USB sticks, some of them have > a Ralink chipset, yet I don't get thoughputs anything near the > 300Mbit that all of the sticks advertise and I would like to ask this > forum if anyone has any hints about why. > > I will describe my system and my test procedure. > > I basically build an access point using HostAPD (0.7.3) using DHCP and > I transfer a file using Samba for the shared folders functionality, > from a Linux 3.4.7 system into a Windows system. If the trasfer is > done via our Gigabit network, I get transfer rates of 100 Mbit (which > is the maximum that the Linux box can deliver as it has a 100 Mbit > adapter). When transfering the file via Wireless, and after tweaking > the HostAPD conf file a bit I could get a maximum of 3.3 MBps (~ 27 > Mbit) which is 10% from the advertised speed. My Windows PC has an > Atheros AR9287 which is 2T2R as well and thus is be able to handle the > 300 Mbit. Both devices are 1m apart and I chose channel 6 which is the > least polluted one in my environment. > > I am mainly interested in the Access Point transfers, yet I have > tested the Ad-Hoc connection as well (yet only 802.11.g 54Mbit) and > with that I get even slower transfer rates. > > USB Chipset > Ralink 3072 > > Linux box: > Kernel 3.4.7 Vanilla > > HostAPD conf: > #=============================== > interface=wlan2 > driver=nl80211 > ssid=LLS0610007xx > channel=6 > hw_mode=g > max_num_sta=5 > ctrl_interface=/var/run/hostapd > ignore_broadcast_ssid=0 > rts_threshold=2347 > fragm_threshold=2346 > macaddr_acl=0 > logger_syslog=-1 > logger_syslog_level=0 > logger_stdout=-1 > logger_stdout_level=0 > dump_file=/tmp/hostapd.dump > ieee80211n=1 > ht_capab=[HT40-][SHORT-GI-20][SHORT-GI-40][TX-STBC][RX-STBC12] > > auth_algs=1 > wpa=2 > wpa_key_mgmt=WPA-PSK > wpa_pairwise=CCMP > wpa_group_rekey=86400 > wpa_gmk_rekey=86400 > wpa_passphrase=0123456789 > #=============================== > > > iw list: > > Wiphy phy4 > Band 1: > Capabilities: 0x2f2 > HT20/HT40 > Static SM Power Save > RX Greenfield > RX HT20 SGI > RX HT40 SGI > TX STBC > RX STBC 2-streams > Max AMSDU length: 3839 bytes > No DSSS/CCK HT40 > Maximum RX AMPDU length 65535 bytes (exponent: 0x003) > Minimum RX AMPDU time spacing: 2 usec (0x04) > HT RX MCS rate indexes supported: 0-15, 32 > TX unequal modulation not supported > HT TX Max spatial streams: 2 > HT TX MCS rate indexes supported may differ > Frequencies: > * 2412 MHz [1] (0.0 dBm) > * 2417 MHz [2] (0.0 dBm) > * 2422 MHz [3] (0.0 dBm) > * 2427 MHz [4] (0.0 dBm) > * 2432 MHz [5] (0.0 dBm) > * 2437 MHz [6] (0.0 dBm) > * 2442 MHz [7] (0.0 dBm) > * 2447 MHz [8] (0.0 dBm) > * 2452 MHz [9] (0.0 dBm) > * 2457 MHz [10] (0.0 dBm) > * 2462 MHz [11] (0.0 dBm) > * 2467 MHz [12] (0.0 dBm) (passive scanning, no IBSS) > * 2472 MHz [13] (0.0 dBm) (passive scanning, no IBSS) > * 2484 MHz [14] (0.0 dBm) (passive scanning, no IBSS) > Bitrates (non-HT): > * 1.0 Mbps > * 2.0 Mbps (short preamble supported) > * 5.5 Mbps (short preamble supported) > * 11.0 Mbps (short preamble supported) > * 6.0 Mbps > * 9.0 Mbps > * 12.0 Mbps > * 18.0 Mbps > * 24.0 Mbps > * 36.0 Mbps > * 48.0 Mbps > * 54.0 Mbps > max # scan SSIDs: 4 > max scan IEs length: 2257 bytes > Coverage class: 0 (up to 0m) > Supported Ciphers: > * WEP40 (00-0f-ac:1) > * WEP104 (00-0f-ac:5) > * TKIP (00-0f-ac:2) > * CCMP (00-0f-ac:4) > Available Antennas: TX 0 RX 0 > Supported interface modes: > * IBSS > * managed > * AP > * AP/VLAN > * WDS > * monitor > software interface modes (can always be added): > * AP/VLAN > * monitor > interface combinations are not supported > Supported commands: > * new_interface > * set_interface > * new_key > * new_beacon > * new_station > * set_bss > * authenticate > * associate > * deauthenticate > * disassociate > * join_ibss > * remain_on_channel > * set_tx_bitrate_mask > * action > * frame_wait_cancel > * set_wiphy_netns > * set_channel > * set_wds_peer > * Unknown command (84) > * Unknown command (87) > * Unknown command (85) > * connect > * disconnect > Supported TX frame types: > * IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 > 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > * managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 > 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > * AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 > 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > * AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 > 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > * mesh point: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 > 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > * P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 > 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > * P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 > 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0 > Supported RX frame types: > * IBSS: 0xd0 > * managed: 0x40 0xd0 > * AP: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0 > * AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0 > * mesh point: 0xb0 0xc0 0xd0 > * P2P-client: 0x40 0xd0 > * P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0 > HT Capability overrides: > * MCS: ff ff ff ff ff ff ff ff ff ff > * maximum A-MSDU length > * supported channel width > * short GI for 40 MHz > * max A-MPDU length exponent > * min MPDU start spacing > Device supports TX status socket option. > Device supports HT-IBSS. > > > Does anyone have a clue? First of all, 802.11 is a half-duplex medium, thus your throughput is limited to roughly half the reported rate. In addition, many conditions will prevent even reaching that value for 802.11n. Read http://compnetworking.about.com/od/wireless/f/80211n-300-mbps.htm for a description of what it takes to reach the value. My best performance has been ~70 Mbps on a TP-Link TL-WN722N, which uses ath9k_htc. Larry