[CentOS-devel] Why does CentOS 5 claim to be i386 compatible when it's really not?

Martin Jungowski

martin at rhm.de
Mon Dec 13 10:02:05 UTC 2010

On Sun, 12 Dec 2010 17:08:24 -0500 Peter A wrote:
> Over the past few years, i386 has become a synonym for 32bit rather than
> "it will run on a 80386". The RPM package for the kernel is correctly
> labeled as i686, its just the name of the distro that remained i386. 

That's why I'm asking whether or not it would make more sense to rename 
the distro to i686 instead. It might make perfect sense in a very 
colloquial way but from a technical point of view i386 suggests 32-bit 
80386 compatibility. Either way, it's just a suggestion and general 
wondering since I wasn't aware of what i386 had become in the US.

> The main reason for the higher requirements is the CMOV instruction.
> Search google for i386 CMOV and you will find the reason why and that 
> this affects most other distributions the same way.

I'm familiar with the CMOV instruction. I wasn't aware that it wasn't 
part of Intel's initial 80386 32-bit instruction set, thanks a lot. 
Funnily enough I found unanswered questions on the Ubuntu forums 
inquiring whether their i386 ISO wasn't really i386 because it didn't 
load on an 80386 processor ;)

I've installed CentOS 4.8 by the way. Takes a while to load but once it's 
up and running it's surprisingly fast on that 500 MHz 'beast' :)


Rieke Computersysteme GmbH
Hellerholz 5
D-82061 Neuried
Email: martin[at]rhm[dot]de

More information about the CentOS-devel mailing list