on-disk format across architectures

Hi,

I'm aware that the on-disk format changes between releases. However,
I'd like to know if it also varies across architectures.

Specifically, my home directory is NFS-mounted and I'd like to be
able to run postmaster on both Sparc Solaris and Intel Linux
using the same -D option (obviously not at the same time!).

 cheers,
 Tom.