x86_64 (64-bit) Fedora on 32-bit machine?

[billquinn]

I have two networked computers: a 32-bit machine running F12 and a 64-bit machine running F13. I'd like to install the new F14 on both. Is x86_64 (64-bit) Fedora backward compatible? Will it run on the 32-bit machine so I don't have to get two different versions of F14--x86_64 (64-bit) and i386 (32-bit)?

Thanks.

[jpollard]

Nope.

Your problem is that the addressing (64bit) will not work with 32 bit hardware.

Upward compatibility is there, the 64 bit kernel can use 32 bit user space
because of the downward compatibility of the hardware, but 64 bit
binaries will not work on a 32 bit hardware.

Now, the 64 bit hardware can run a 32 bit OS - again this is because of the
downward compatibility. The only time 64 bit really help is if you have more
than 4 GB of memory - or want to run processes that are using more than
a 32 bit virtual addressing.

There is a relatively small performance penalty for running 32 bit software
on 64 bit hardware, but not enough to really notice unless you are running
some heavy computational applications (ray tracing, finite element analysis
...).

[billquinn]

Jpollard,

Thanks for your quick and thorough reply. It was most helpful. Looks like I'll stick to the 32-bit version of F14 for both computers.

Bill