I have swapped out my Realtek 8192SE based card from my laptop with a Intel Wifi Link 5100. Battery life seems to be substantially improved and appears comparable to that under Win7 now. I am now wondering, is it due to potentially inefficient binary drivers by other manufacturers or something? Looks like an interesting research topic. If anyone has any ideas, let me know.
I tested a Rosewill RNX-G1 USB Wireless adapter under Ubuntu 10.04 Lucid. It worked out of the box. As soon I inserted the adapter, Ubuntu detected it and network manager started showing available networks in about 10-20 seconds. I have been able to connect to WPA2 personal as well as WPA2 enterprise (PEAP) connection without problems and with good signal strenght. Ubuntu used the RT8187 driver. Recommended for use with ubuntu. Note that it works at Wifi G speeds and not N but is pretty cheap on newegg.
I bought a Lenovo Thinkpad X100e with a dual-core AMD Neo X2 L335 processor. My model comes with 2GB RAM and Win7 Pro. I have also installed Ubuntu 10.04 (Lucid Lynx) and am dual-booting Windows and Ubuntu. There are several things that you should note:
1. Installation of fglrx is absolutely necessary otherwise the machine will freeze randomly.
2. The wifi driver does not work out of the box. However you can follow this guide: http://justinsomnia.org/2010/02/ubuntu-on-a-lenovo-thinkpad-x100e/
The wifi driver works fine with WPA2 personal but it is very unstable with WPA2-PEAP. It also seems to have a problem with powertop. If you have this driver installed, then launching powertop will freeze your machine. I finally gave up, blacklisted the driver (added r8192se_pci to /etc/modprobe.d/blacklist.conf) and am using a USB wireless adapter instead. I had tried the latest realtek drivers (version 0015) from realtek site but made no difference.
3. The machine is much more responsive with Ubuntu than with Win7 Pro with the original configuration. I have finally upgraded RAM to 3GB and now Win7 runs smoothly too.
4. If you keep the wireless disabled, then the power consumption of the laptop according to powertop is around 10.5 to 13W in powersave mode which should give you about 4.5 hours of battery life if you are just doing lets say some word editing with occasional CPU intensive activity.
