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    SubjectRe: rt61pci - bad performance
    (cc's added)

    On Sun, 08 Aug 2010 11:49:49 +0200
    Andreas <andihartmann@01019freenet.de> wrote:

    > Hello!
    >
    > I've got the following hardware
    >
    >
    > 01:05.0 Network controller: RaLink RT2561/RT61 rev B 802.11g
    > Subsystem: Micro-Star International Co., Ltd. Device b833
    > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop-
    > ParErr- Stepping- SERR- FastB2B- DisINTx-
    > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=slow >TAbort-
    > <TAbort- <MAbort- >SERR- <PERR- INTx-
    > Latency: 128, Cache Line Size: 64 bytes
    > Interrupt: pin A routed to IRQ 21
    > Region 0: Memory at cc000000 (32-bit, non-prefetchable) [size=32K]
    > Capabilities: [40] Power Management version 2
    > Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
    > PME(D0-,D1-,D2-,D3hot-,D3cold-)
    > Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
    > Kernel driver in use: ndiswrapper
    >
    >
    > running on a 32bit notebook with kernel 2.6.34-12-desktop (OpenSuSE
    > 11.3). There is no difference between the compat-wireless-modules
    > 2010-07-20 and the original modules shipped with the openSuSE 11.3 kernel.
    >
    > If the rt61-chip is connected to a AP using rt61pci, the best
    > throughput, which can be achieved (at the same place), is about 1,7
    > MBytes/s.
    >
    > kernel: [ 656.112190] cfg80211: Calling CRDA to update world regulatory
    > domain
    > kernel: [ 656.112267] cfg80211: Calling CRDA for country: DE
    > kernel: [ 656.169518] cfg80211: Regulatory domain changed to country: DE
    > kernel: [ 656.169524] (start_freq - end_freq @ bandwidth),
    > (max_antenna_gain, max_eirp)
    > kernel: [ 656.169528] (2400000 KHz - 2483500 KHz @ 40000 KHz),
    > (N/A, 2000 mBm)
    > kernel: [ 656.169532] (5150000 KHz - 5350000 KHz @ 40000 KHz),
    > (N/A, 2000 mBm)
    > kernel: [ 656.169535] (5470000 KHz - 5725000 KHz @ 40000 KHz),
    > (N/A, 2698 mBm)
    > kernel: [ 656.206228] rt61pci 0000:01:05.0: PCI INT A -> GSI 21 (level,
    > low) -> IRQ 21
    > kernel: [ 656.219941] phy0: Selected rate control algorithm 'minstrel'
    > kernel: [ 656.222216] Registered led device: rt61pci-phy0::radio
    > kernel: [ 656.222658] Registered led device: rt61pci-phy0::assoc
    > kernel: notebook1 ifup: wlan0 device: RaLink RT2561/RT61 rev B
    > 802.11g
    >
    >
    >
    > wlan0 IEEE 802.11bg ESSID:"--------"
    > Mode:Managed Frequency:2.412 GHz Access Point: some AP
    > Bit Rate=1 Mb/s Tx-Power=5 dBm
    > Retry long limit:7 RTS thr:off Fragment thr:off
    > Encryption key:off
    > Power Management:off
    > Link Quality=38/70 Signal level=-72 dBm
    > Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
    > Tx excessive retries:0 Invalid misc:0 Missed beacon:0
    >
    > The throughput is measured with ping -f -s 7000 and xosview -n.
    >
    >
    >
    >
    > If I'm using ndiswrapper with the windows driver, first of all, I can
    > see additional information in iwconfig:
    >
    > wlan0 IEEE 802.11g ESSID:"--------"
    > Mode:Managed Frequency:2.412 GHz Access Point: some AP
    > Bit Rate=54 Mb/s Tx-Power:20 dBm Sensitivity=-121 dBm
    > RTS thr=2347 B Fragment thr=2346 B
    > Encryption key:some key Security mode:restricted
    > Power Management:off
    > Link Quality:62/100 Signal level:-56 dBm Noise level:-96 dBm
    > Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
    > Tx excessive retries:0 Invalid misc:0 Missed beacon:0
    >
    >
    > There is a switch for sensitivity (which is not supported with rt61pci)
    > and the link quality compared with ndiswrapper is worse (38% to 62%).
    >
    > The following is remarkably too:
    > ndiswrapper uses a Tx-Power of 20 dBm, rt61pci only 5 dBm. I don't know,
    > why rt61pci uses 5 dBm. It's a hard limit and I can't set it on a value
    > higher than 5 unless the driver is patched. Nevertheless, setting a
    > higher value (of 20 dBm) by patch does not mean to get a better performance.
    > Ndiswrapper shows an encryption key, rt61pci not. Does it mean, that
    > rt61pci doesn't use hardware encryption?
    >
    >
    > With ndiswrapper, the rt61pci-chip achieves a throughput of 2,6 MBytes/s
    > - that's about 1 MByte/s more than rt61pci.
    >
    > I have to say, that the difference between rt61pci and ndiswrapper gets
    > worse if the link quality is getting more badly. Or in other words:
    > ndiswrapper handles bad connections better then rt61pci.
    >
    >
    > Do you have any idea to get rt61pci working as fast as ndiswrapper?
    >



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