I have install Xubuntu 12.04 LTS. Everything works fine except that when I watch a movie especailly fast action scene. It has a hroizontal line running across the screen. I have install the nVidia driver as recommended and try severall setting but fail. When I switch to Kubuntu the problem gone.
So I was wondering whether there is a difference between the 2 distro and how to solve the problem? I like Xubuntu because of its light weight. Thanks in advance.
Hmm, I don't know what to suggest. It's probably some lightweight alternative bit of software that Xubuntu uses that is causing the problem. Perhaps a driver or a codec or something! Either way there is something that KDE uses that XFCE does not. But I couldn't tell you exactly what it is!
With most Linux distros, you can install as many desktop environments as you like and you can usually choose which desktop session to use at the login screen (depending on the chosen Display/login manager). And this is true of the Ubuntu family of distros.
So if the problem is fixed in Kubuntu, but you want a lighter desktop experience you could always try installing the Xubuntu/XFCE desktop (not the distro) on top of Kubuntu. After installing the xubuntu desktop and then logging out and switching to an xfce session, your problem MIGHT be fixed.
Alternatively, there is a newish, lightweight, QT-based desktop called Razor-QT which offers a lightweight desktop experience for KDE users. The desktop itself looks and feels a bit like Gnome2 or Openbox and is really fast and responsive compared to the full-fat KDE experience, which can be quite slow on lower end machines!
To install Razor-QT in a Ubuntu based distro, open up a command line and enter the following commands:
Razor-QT doesn't have it's own network management applet yet (the KDE network management applet is a Plasma plugin, which Razor doesn't use). So in order to manage connections to wired or wireless networks, you'll need to install the gnome network manager applet:
sudo apt-get install gnome-network-manager
On Ubuntu based distros, the installer for the gnome-network-manager package automatically sets the applet to run at startup and ensures it doesn't get started during KDE desktop sessions (avoiding conflicts with the KDE network manager applet).
Once Razor-QT is installed, you just log out and select Razor-QT as the default desktop session before logging back in again and you instantly have a lighter desktop, but still using all of the QT goodness of KDE.
Razor has a limited number of simple widgets which you can use to customise your desktop, it also has a few settings utilities which allow you to tweak Razor's look and feel a little. You can also access the KDE settings to customise how QT apps will appear and make other KDE-based settings. NOTE: Changes to the KDE settings will affect Razor and KDE!
Also Razor can be used with several window managers, I've not seen the full list of window managers it supports, but I know it works with Kwin (KDE's default window manager) and Openbox. So you could install and use Openbox as your WM if you didn't want to use kwin (making Razor even lighter on resources!). By default Razor uses kwin.
I've currently got Kubuntu 12.04 installed on my laptop. But I wanted a more lightweight desktop experience, so I initially installed Openbox and DWM (lightweight tiling WM) alongside the default KDE desktop.
I was using Openbox sessions for general desktop usage and DWM sessions for project work or administrative tasks (can't beat a tiling WM when you've got lots of text files and/or terminals open!). After hearing good things about the Razor-QT desktop over the last year or so, so I finally decided to give it a try. I've been using Razor-QT on my laptop for a few weeks now and I've got to say I'm loving it so far!
Nowadays I use Razor for general desktop sessions, with Openbox as its WM (making it a lot lighter on resources) and I still use DWM for project work. I only use a full-fat KDE/Plasma desktop session when I want to show off some bling in front of non-Linux users!
^^ True story ;)
Oh and I haven't noticed any problems with video playback using any of the above DE's/WM's in combination with Kubuntu! :)