Choose this to take full advantage of computers based on the AMD64 or EM64T architecture (e.g., Athlon64, Opteron, EM64T Xeon, Core 2). If you have a non-64-bit processor made by AMD, or if you need full support for 32-bit code, use the Intel x86 images instead.
Installation Requirements from Ubuntu's site -
Desktop installation
Most people will want to install a desktop system such as Ubuntu, Kubuntu, or Xubuntu. A desktop system is typically used for personal computing tasks and has a graphical user interface.
Bare Minimum requirements
It should be possible to get Ubuntu running on a system with the following minimum hardware specification, although it is unlikely that the system would run well. You should use the Alternate install CD to attempt such an installation.
* 300 MHz x86 processor
* 64 MB of system memory (RAM)
* At least 4 GB of disk space (for full installation and swap space)
* VGA graphics card capable of 640x480 resolution
* CD-ROM drive or network card
Recommended minimum requirements
Ubuntu should run reasonably well on a computer with the following minimum hardware specification. However, features such as visual effects may not run smoothly.
* 700 MHz x86 processor
* 384 MB of system memory (RAM)
* 8 GB of disk space
* Graphics card capable of 1024x768 resolution
*Sound card
*A network or Internet connection
Note: All 64-bit (x86-64) PCs should be able to run Ubuntu. Use the 64-bit installation CD for a 64-bit-optimised installation.
Recommended for visual effects
Visual effects provide various special graphical effects for your desktop to make it look and feel more fun and easier to use. If your computer is not powerful enough to run visual effects, you can turn them off and will still have a usable Ubuntu desktop.
Visual effects are turned on by default if you have a graphics card which is supported. For information on supported graphics cards, see DesktopEffects.
* 1.2 GHz x86 processor
* 384 MB of system memory (RAM)