"Archlinux has been optimised for i686 architecture to a very high extent. All modern 32bit capable standard x86 CPUs support i686. This is right from the old Pentium Pro CPUs to the new Nehalems. Its also optimised for modern AMD CPUs. For those who need a 64bit distro, there is an x86_64 (commonly known as amd64) variant for archlinux.
"Unlike arch, most common distros are designed for i386, i486 or i586 architectures, which are architectures very few existing systems use and are long obsolete. So Arch’s i686 optimisation carries with it several speed boosts, and reviews commonly go that next to Gentoo and CRUX, arch is the fastest distro around."
