FreeBSD vs Linux - size matters

As we recently migrated most of our servers from CentOS to FreeBSD, here is a difference between minimum system requirements of Ubuntu Server CLI Installation and FreeBSD 9:

OS FreeBSD 9 Ubuntu Server (CLI) Installation
Processor a 486 or better processor 300 MHz x86 processor
System memory (RAM) 64 MB 128 MB
Disk space 1.1 GB 1 GB

The major difference though between FreeBSD and Linux distros comes from the concept of FreeBSD “base system” which is clearly described by Matt Fuller.