Excerpt from a Linux-wireless discussion (this is Linux kernel developer's list for wireless interfaces) They asked me to do some tests: the major one was MMIO tracing the driver: > You need to enable MMIO tracing support in your kernel config, and > recompile your kernel (assuming it is not enabled already - distros > usually disable the entire tracing framework by default). Then: > -Mount debugfs to /debug. (Usually it is mounted by default, but some > distros like to mount it @ /sys/kernel/debug instead - remount it to > /debug.) > -"echo mmiotrace > /debug/tracing/current_tracer" > -"cat /debug/tracing/trace_pipe > trace.txt &" - at this point, tracing begins. > -Load r8187b and connect. > -"echo "Driver loaded!" > /debug/tracing/trace_marker" > -"echo nop Ok here are some news: 1) The rtl8187b problem is a know bug in Ubuntu since forever - bug #215802 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/215802 2) Tryied the Realtek driver found in: http://ubuntuforums.org/showthread.php?t=1446894 (rtl8187B_linux_26.1056.1112.2009.release.tar.gz ) - as seno said here on the list in 14-05-2010 17:20:02 It installs a module called r8187b, witch I managed to use ONCE, after it installed, then after it disconnected it would not connect again, and after I rebooted there was no more wi-fi interface (!!!) ifconfig and iwconfig confirm that my wi-fi card (wlan0) is nowhere to be found 5) Rate seems weird on this card. If I define the rate with "iwconfig wlan0 rate 11M" it gives the best download speed, even if I rase this to 24M or 54M I get at least a 40% difference, same if I lower the rate. Maybe what Hin-Tak Leung (2010-04-03) said about the Minstrel algorithm? Could we try to install both Minstrel and older algorithms side by side and make a comparison? from what I read here: http://wireless.kernel.org/en/developers/Documentation/mac80211/RateControl/minstrel "Further, it means that the 1 Mbps rate (which typically has a high probability of successful transmission) will not be used in preference to the 11 Mbps rate." But my rate is always a defaulted 1Mb/s on bootup. I put it to 11M manually and the connection improves dramatically 4) Ran the mmiotrace on the rtl8187 driver, it all seems gibberish to me ;) one while it was at 1m from the router giving me top speed (same as Win7): trace1.txt: VERSION 20070824 PCIDEV 0000 10390671 0 d0000000 0 0 0 0 0 0 8000000 0 0 0 0 0 0 agpgart-sis PCIDEV 0008 10390003 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PCIDEV 0010 10390968 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PCIDEV 0015 10395513 10 1f0 3f6 170 376 1081 0 0 8 0 8 0 10 0 0 pata_sis PCIDEV 0018 10397001 14 d8404000 0 0 0 0 0 0 1000 0 0 0 0 0 0 ohci_hcd PCIDEV 0019 10397001 15 d8405000 0 0 0 0 0 0 1000 0 0 0 0 0 0 ohci_hcd PCIDEV 001b 10397002 16 d8406000 0 0 0 0 0 0 1000 0 0 0 0 0 0 ehci_hcd PCIDEV 0020 10390191 13 d8407000 1001 0 0 0 0 0 80 80 0 0 0 0 0 sis190 PCIDEV 0028 10391183 11 10c9 10bd 10c1 10b9 10a1 0 0 8 4 8 4 10 0 0 sata_sis PCIDEV 0030 1039000a 18 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pcieport PCIDEV 0038 1039000a 19 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pcieport PCIDEV 0078 10397502 12 d8400000 0 0 0 0 0 0 4000 0 0 0 0 0 0 HDA Intel PCIDEV 00f8 10390004 1a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pcieport PCIDEV 0100 10396351 10 c0000008 d8000000 9001 0 0 0 2 10000000 20000 80 0 0 0 0 PCIDEV 0300 197b2382 10 d8100000 0 0 0 0 0 d8500000 100 0 0 0 0 0 10000 sdhci-pci PCIDEV 0302 197b2381 10 d8100400 0 0 0 0 0 0 100 0 0 0 0 0 0 PCIDEV 0303 197b2383 10 d8100800 0 0 0 0 0 0 100 0 0 0 0 0 0 jmb38x_ms ** then when it was about 10m - failed to connect (Windows 7 connects normally) trace2.txt VERSION 20070824 PCIDEV 0000 10390671 0 d0000000 0 0 0 0 0 0 8000000 0 0 0 0 0 0 agpgart-sis PCIDEV 0008 10390003 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PCIDEV 0010 10390968 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PCIDEV 0015 10395513 10 1f0 3f6 170 376 1081 0 0 8 0 8 0 10 0 0 pata_sis PCIDEV 0018 10397001 14 d8404000 0 0 0 0 0 0 1000 0 0 0 0 0 0 ohci_hcd PCIDEV 0019 10397001 15 d8405000 0 0 0 0 0 0 1000 0 0 0 0 0 0 ohci_hcd PCIDEV 001b 10397002 16 d8406000 0 0 0 0 0 0 1000 0 0 0 0 0 0 ehci_hcd PCIDEV 0020 10390191 13 d8407000 1001 0 0 0 0 0 80 80 0 0 0 0 0 sis190 PCIDEV 0028 10391183 11 10c9 10bd 10c1 10b9 10a1 0 0 8 4 8 4 10 0 0 sata_sis PCIDEV 0030 1039000a 18 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pcieport PCIDEV 0038 1039000a 19 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pcieport PCIDEV 0078 10397502 12 d8400000 0 0 0 0 0 0 4000 0 0 0 0 0 0 HDA Intel PCIDEV 00f8 10390004 1a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pcieport PCIDEV 0100 10396351 10 c0000008 d8000000 9001 0 0 0 2 10000000 20000 80 0 0 0 0 PCIDEV 0300 197b2382 10 d8100000 0 0 0 0 0 d8500000 100 0 0 0 0 0 10000 sdhci-pci PCIDEV 0302 197b2381 10 d8100400 0 0 0 0 0 0 100 0 0 0 0 0 0 PCIDEV 0303 197b2383 10 d8100800 0 0 0 0 0 0 100 0 0 0 0 0 0 jmb38x_ms *** All the steps asked by Gábor were done. Thanks all you guys. Rogerio