Today, I’m running OpenSuse-11.1 with a 32 bit kernel on a PC powered by an AMD-Athlon (64bits); All works well for me. ( I’m not a great power-consumer : no game, light graphic processings, …).
Question 1 : is it possible to upgrade from 11.2/32 bits to 11.2/64 bits ?
Question 2 : Should I have really anything to get in upgrading to 64 bits-kernel ?
You can’t do an in-situ upgrade. Essentially the x86-64 arch is like a different CPU. So it would have to be an fresh install. But you can preserve /home. But you should do a backup of it and also key config files, just in case Murphy is tempted. There are HOWTOs on this, do a search on the forums.