Edimax EW-7811Un review

My Thinkpad X60s came with a miniPCI wireless card, using the Atheros 5k chipset. It's only compatible with up to 802.11g, so it never had fantastic range or speeds, but it was certainly adequate. However, for the past several months now it's been acting very flaky. Connections will drop out frequently, and every now and then it will essentially just stop working, with dmesg filling up with strange messages about calibration timeouts or "unknown errors". Usually a robust round of unloading and reloading the ath5k kernel modules and/or iwconfig downing and uping the interface and/or rfkill unblocking the interface, I can get it working again without having to reboot, but it's a royal pain in the ass. Especially because lately it's been following a pattern of working fine for a whole day or two and then needing constant attention for hours.

I initially thought about buying a new miniPCI device to replace it, but it turns out this is not straightforward. Thinkpads have a list of miniPCI device IDs stored in the BIOS and only devices on that whitelist will actually work. Of course, the whitelist is limited to Lenovo branded devices which cost a lot more than equivalent non-Lenovo devices (all this according to ThinkWiki). For the record, this is absolutely a dick move by Lenovo and they should be ashamed. That said, when thinking of other companies who make laptops with strong reputations for excellent quality, I come up with Apple and Sony, who are not exactly outstanding people either.

Anyway, I decided to look into USB wifi adaptors, and the state of the art with these things is amazing. You can buy 802.11n compatible adaptors which are about as small as they practically could be for between 10 and 20 US dollars. I bought the Edimax EW-781Un off Amazon for $9.99. I've only had it for about 24 hours so far, but at this point I am exceptionally pleased with it. It sticks out from the side of my Thinkpad maybe 6 or 7 mm (about a quarter of an inch), so it basically doesn't change the overall form-factor of the machine at all. It plugs in solidly so I don't think there's any risk of it coming out by accident. I think I could leave it in there all the time and still easily carry the Thinkpad in the same bags I always have. There's a blue LED in there which blinks on network activity. I wouldn't go so far as to describe it as annoying, but it does kind of make it difficult to completely forget the Edimax exists. I think if the LED were omitted it would be exceptionally easy to plug this thing in and just utterly forget about it forever after. The signal strengths I see with the Edimax are, of course, a lot higher than I got out of the old 802.11g device. The speeds are faster, and it hasn't cut out on me yet.

Getting it to work on Debian Squeeze was really straightforward. Edimax have a Linux driver you can download from their website. It's a zip file which contains, among other things (including instructions on how to install the driver) a simple install script which compiles the modules, resulting in a file 8192cu.ko that you can use insmod to load. Be aware that you will need to have the appropriate linux-headers package installed (for me this was linux-headers-2.6.32-5-686) in order to be able to do the compilation. After you've loaded the module, the new interface should show up in iwconfig and from there you can set up networking however you normally do (which, for me, is with wicd-ncurses).

This device is also apparently compatible with NetBSD 6, so it seems like this is a really good choice for people who want something that works with a wide range of geeky OSes. It's definitely a good buy given its ridiculously low price.