[rt2x00-users] rt3572: comparison between rt2800usb (Linux 3.6.4) vs. rt5572sta

Andreas Hartmann andihartmann at 01019freenet.de
Sun Nov 4 23:49:44 AEDT 2012


Hello!

I compared the driver rt2800usb (Linux 3.6.4) with rt5572sta. The
device used for comparison is Linksys WUSB600Nv2 (rt3572).
As AP, Linksys WMP600N is used (rt2800pci with
mostly compat-wireless-3.5rc5).

WLAN is 802.11n, 2.4 GHz, 40 MHz, EAP-TLS, AES.

STA-machine runs with a Core i5 M460 CPU and 64bit Linux.



1. run: rt2800usb out of the box
================================

Doesn't work at all with netperf. After a few seconds or a few minutes,
I get this error:

phy0 -> rt2x00usb_vendor_request: Error - Vendor Request 0x07 failed for offset 0x101c with error -71.

The device now is dead and must be reinserted combined with reloading
the module.

Working with ssh (without using tunneled X - just a konsole, is
absolutely unusable. It takes about one second for each sign typed in.)



2. run: rt2800usb powermanagement disabled (iwconfig wlan1 power off)
=====================================================================

This works. See the attached file. The values are:

Rx MAERTS rt2800usb
Tx STREAM rt2800usb
Tx SENDFILE rt2800usb


iwconfig (example from the beginning)

wlan1     IEEE 802.11abgn  ESSID:"SSID"
          Mode:Managed  Frequency:2.422 GHz  Access Point: 11:22:33:44:55:66
          Bit Rate=150 Mb/s   Tx-Power=20 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=51/70  Signal level=-59 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:1218  Invalid misc:9   Missed beacon:0


Striking:
Linksys WUSB600Nv2 is a 300Mb/s device. But it is maximally driven with
150Mb/s. There seems to be something broken.



3. run: rt5572sta
=================

See attached file. The values are:

Rx MAERTS rt5572sta
Tx STREAM rt5572sta
Tx SENDFILE rt5572sta

iwconfig (at the end of the test)

ra0       Ralink STA  ESSID:"SSID"  Nickname:"RT3572STA"
          Mode:Managed  Frequency=2.422 GHz  Access Point: 11:22:33:44:55:66
          Bit Rate=300 Mb/s
          RTS thr:off   Fragment thr:off
          Encryption key:1111-1111-1111-1111-1111-1111-1111-1111 [3]   Security mode:restricted   Security mode:open
          Link Quality=73/100  Signal level:-67 dBm  Noise level:-83 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0



Conclusion:
===========

With rt2800usb, there are missing 3.4 Mb/s in the middle compared to
rt5572sta (Rx) and 1.8 Mb/s Tx.



The tests (each about 1 hour) where done with this little script
running on the STA:

-------------------------------------------------------
#!/bin/sh

host="IP"
while true ; do
    netperf -t TCP_STREAM -H $host
    netperf -t TCP_MAERTS -H $host
    netperf -t TCP_SENDFILE -H $host
done
-------------------------------------------------------

Each single run of netperf is one sample in the sheet.

The STA was located on another floor as the AP with one wall and a
reinforced concrete floor in between.


Kind regards,
Andreas
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