Slow network
This is an old issue which I have experienced since 11.10. It's because of the compatibility of iwlagn drivers with 802.11n. 802.11n, which was released in 2009, is the latest standard of WLAN (except 802.11ac which is still under development). Anyway it has the maximum achievable data rate compared with other 802.11 standards. Therefore it's preferred by iwlagn and, unfortunately in our case, enabled by default. To work around with this issue, just simply disable 802.11n by appending the following content to anyone of conf. files under /etc/modprobe.d/options iwlwifi 11n_disable=1
Note: the iwlwifi is the actual module that has been used on your system. It might be iwlwifi or iwlagn (or something else which I don't know yet). To figure out which one you are using, you might use the following command to get a list of active modules.lsmod
Unable to use dual-monitor
When trying to set up dual-monitor using the standard way (i.e. through Display), I had the following error:
The selected configuration for displays could not be applied requested position/size for CRTC 147 is outside the allowed limit: position=(1920, 180), size=(1440, 900), maximum=(1920, 1920)It's about the configuration of XORG, a simple solution is to adjust the Virtual section in /etc/X11/xorg.conf into the one fits your 2nd monitor's resolution. For example:
Section "Screen"
Identifier "Default Screen"
Device "Default Video Device"
DefaultDepth 24
SubSection "Display"
Virtual 1920 1080
EndSubSection
EndSection