Re: Features/ArchitectureSupport - changing what we build for

[Jan Kratochvil <jan kratochvil redhat com>]

On Fri, 30 Jan 2009 21:35:05 +0100, Bill Nottingham wrote:
> Kevin Fenzi (kevin scrye com) said, in the FESCo meeting summary: 
> > * Architecture Support
> >   https://fedoraproject.org/wiki/Features/ArchitectureSupport
[...]
> - install x86_64 kernel on 32-bit OS where appropriate

Could you please provide more public background for this FESCo decision?
Particularly why not to automatically install the whole x86_64 distro where
appropriate?  The DVD media should contain both arches as in the real world
found out the users are not aware if they have 64bit-capable hardware.

x86_64 provides CPU instruction set + ABI improvements which usually overcome
its only performance disadvantage of larger addresses, some benchmarks at:
http://www.amd64.org/fileadmin/user_upload/pub/64bit_Linux-Myths_and_Facts.pdf

Guessing some software (codecs?) may fallback on 64-bit to unoptimized C code
instead of some assembly one but Fedora would at least show the usefulness of
the updates of such software for the x86_64 arch.


Regards,
Jan