Ubuntu 32bit only supports 3 GB of RAM so if you have 4, only 3 will be used. You can use the 64bit version for all 4GB of RAM memory to work, or follow the instructions in this post to make the 32bit version of Ubuntu to work with 4GB or RAM.
Firstly, please note that to achieve this, you must install the Ubuntu Server Kernel which has Phisical Extencion Address Enabled (PAE) enabled thus allowing Ubuntu to see all 4 GB of RAM. You can also compile the 32 Kernel desktop version yourself, and enable PAE but that's difficult to explain so I'll not cover that :). Once, that was easily done with Kernelcheck, but now kernel.org changed something which made Kernelcheck to stop working. Another solution would be to just install the 64bit Ubuntu.
Firstly, please note that to achieve this, you must install the Ubuntu Server Kernel which has Phisical Extencion Address Enabled (PAE) enabled thus allowing Ubuntu to see all 4 GB of RAM. You can also compile the 32 Kernel desktop version yourself, and enable PAE but that's difficult to explain so I'll not cover that :). Once, that was easily done with Kernelcheck, but now kernel.org changed something which made Kernelcheck to stop working. Another solution would be to just install the 64bit Ubuntu.
Installing the Ubuntu Server Kernel is basically for lazy people and should only take 1-2 minutes. If you wish to continue with this solution, follow the steps below:
Open a terminal and paste the following command:
Once the installation is completed, restart your computer and boot into the new Kernel. That's basically it.
Note: This is basically a quick "fix". I strongly suggest newbies don't install this Server Kernel! Why? Because the server version will be more stable, but at the expense of performance and compatibility with various hardware (graphics,sound, etc.). The desktop version will likely provide better user interface response and better handle the latest 3D drivers and other "desktop" hardware. More advanced users should be able to tweak the settings for better responsiveness and hardware compatibility.
[via pmabox]
Open a terminal and paste the following command:
sudo sudo apt-get install linux-headers-server linux-image-server linux-serverOnce the installation is completed, restart your computer and boot into the new Kernel. That's basically it.
Note: This is basically a quick "fix". I strongly suggest newbies don't install this Server Kernel! Why? Because the server version will be more stable, but at the expense of performance and compatibility with various hardware (graphics,sound, etc.). The desktop version will likely provide better user interface response and better handle the latest 3D drivers and other "desktop" hardware. More advanced users should be able to tweak the settings for better responsiveness and hardware compatibility.
[via pmabox]
