Upgrading to 64 bit from a 32 bit installation on FBSD 7

[Kris Kennaway]

Andrew Berry wrote:
> Hi,
> 
> I've got a server which will be upgraded to my "castoff" parts which 
> support amd64. This machine has been running Freebsd since the 5.0 RC's, 
> starting on a P2 233Mhz, upgraded incrementally for a few years - a real 
> testament to the stability of a FreeBSD install! What I've done in the 
> past while upgrading is simply move the drive, and rebuild everything 
> with an updated make.conf optimized for the new processor. Can I simply 
> rebuild the world (or use freebsd-update), and portupgrade everything to 
> rebuild for amd64? Or, will things break as libraries are upgraded which 
> still have 32-bit dependancies on the system?

This is a pretty common question, did you try searching the archives or 
google for the answer?

> Also, AFAIK upgrading to a 64 bit system allows access to additional 
> registers on the CPU, leading to a performance increase. The system will 
> only have 1.5 gigs of RAM, so that's not an issue, but are there any 
> benchmarks out there comparing performance on < 4GB hardware with 32 bit 
> and 64 bit Freebsd?

Performance is not a single number.  Sometimes 64-bit systems can be 
slower, sometimes faster.  Run it on your own workload or look for a 
narrowly tailored benchmark and see what happens for you.

Kris