I am running Ubuntu 13.04 on a 2011 Dell XPS L501X laptop: Intel core i5, Nvidia Geforce GT 420M graphics card, 6gb ram, etc. I had no problems during normal computing, however, after installing and attempting to play minecraft on the machine. Extreme lag led me to investigate things, as this was not a problem with windows. I learned that the Ubuntu os does not seem to recognize my graphics card, and instead mentions Intel Ironlake graphics under my system information. After not finding any appropriate driver downloads on the Nvidia site, I followed the instructions given on http://www.noobslab.com/2012/10/install-latest-nvidia-drivers-in-ubuntu.html. After restarting my computer, I was able to log into my account, but then all that was displayed was my desktop background image. I tried unsuccessfully to fix the problem using some of the instructions provided in the comments on that site, and the end had to reinstall Ubuntu 13.04. After putting all of my documents, software, etc. back on the computer, I tried to install the nvidia drivers via the package available in the software center, once again unsuccessfully. I have now reinstalled Ubuntu 13.04 a third time, and am wondering how I can install these drivers, if there is a way, without messing up the os. I am semi-literate with Linux, and would appreciate help. Thanks!
What you have is hybrid graphics. Basically, you have 2 video cards:
This hybrid graphics solution is intented to work like this:
In order for this magic to happen, some special software is needed, namely the NVIDIA Optimus: http://www.nvidia.com/object/optimus_technology.html
You'll see a (not) nice note in the link above: "Optimus requires Windows 7 or later".
So, no love from NVIDIA to Linux regarding Optimus. See this for a laugh: http://www.youtube.com/watch?v=_36yNWw_07g
What happens in your case is that you ALWAYS end up using the integrated card, no matter what you do (or what NVIDIA driver you install).
What can be done:
Good luck and let us know what happens!