I apologise; this is going to be complicated! First, I have openSuse 11.4 64bit (fresh install) (188.8.131.52-1.2-desktop x86_64) with KDE 4.6.0. Second, I have two USB wireless network adapters; a D-Link DWA-160 Xtreme N Dual Band and a D-Link DWA-140 RangeBooster N. (In linuxese, they are a 07d1:3c11 and a 07d1:3c09). They are both 802.11bgn, the former is dual band, but both seem have the Ralink RT2870 chip. They both work fine with openSuse 11.4 and 11.3, and with Windows 7 and XP. They connect quickly, are rock solid and don’t miss a beat. What is the problem, I hear you say.
To start with, on 11.3, I had problems with getting a connection faster than 54MB/s. With the both Windows I was getting, typically 270MB/s. I did a lot of research, fiddled around, blacklisted this module, downloaded that module, and finally got a fast connection with 11.3. The only problem was that the LED on the adapter stopped working. I know it is not essential, but I find that flashing light reassuring. It tells me the thing is working (it’s a bit like hearing my heart beating; I then know I’m not dead). I stopped fiddling with 11.3, though, because 11.4 came along, and I figured it might solve the problem without further fiddling.
With 11.4 I had some difficulty with knetworkmanager, but used mschlander’s excellent “The Blog is Hot” method for switching to the Gnome network manager. It was good, with a nice signal strength bar chart in the system tray. Then, and only then (it is not installed by default) I found the plasma network manager widget that goes in the system tray. It is excellent, and everything now works perfectly EXCEPT that I still cannot connect at faster than 54MB/s with either adapter. What is the point of having a Belkin all singing and dancing Play Max N+N 300 802.11n router and two 802.11n USB wireless adapters if I can do no better than 802.11g?
I do not seem to be able to do, with 11.4, what I did with 11.3 (it got so complicated that I have forgotten most of it, anyway, but I think it involved rt3572sta as well as the normal rt2870sta. So, if I can work out how to do it, I will post the results of lsusb, lsmod and iwconfig for my 11.4 computer (athlon64x2) and my spare, running 11.3 (athlonxp). I would greatly appreciate any advice as to how to get 802.11n speeds with 11.4 on athlon64x2. My profuse thanks in advance.