Requirement is for Ubuntu is
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