Comment by Macha
5 years ago
The actual minimum x86 CPU for modern Linux is a Pentium 2 (1997, source - https://www.debian.org/releases/stable/i386/ch02s01.en.html).
The practical minimum for a modern distro is probably a Core 2 Duo (2006). You will likely need a lightweight DE on such a system if using it as a desktop.
Some mainstream distros (e.g. Ubuntu) set their requirements higher than that.
That's the minimum CPU for Debian.
The Linux kernel supports the 486 CPU (also used to support the 386, but it was dropped, although it's probably possible to restore it with some work - the 286 can't be easily supported because it lacks 32-bit registers).