[Aurora-sparc-user] My machine is 64 bit, but does it think it is 32 bit?

[Jos van der Ende]

On Mon, 22 Oct 2007 02:56:53 -0500
"Stephen Ware" <sgware at gmail.com> wrote:

> My first instinct was to choose
> "64 bit linux" since the Ultra 10 is a 64 bit machine, but as I was
> reading around online about other SPARC linux ports, I realized that
> perhaps some applications are running in 32 mode.  GAMESS is mostly
> fortran with a tiny bit of C, and I am compiling it from the command
> line.  Should I choose the 64 bit options, or the 32 bit option?

Linux on UltraSPARC systems normally runs with a 64 bit kernel and 32
bit userland, since there is rarely a need for an application to use
64 bit unless it does some heavy computations or address a lot (>4G)
of memory. The later should not be an issue since an U10 has only 1G
max, unless you invested in some exotic memory I am not aware of.

If you are going to do heavy computations, I'd suggest using something
better than ancient hardware like an Ultra 10. Even when clustered, the
performance will probably not be too great. (Though distcc is doing
nicely on my Ultra 5s and Blade 100s.)

So I'd advice using 32 bit. There's a good chance 64 bit won't run or
even compile, unless there is a 64 bit version of glibc installed.


-- 
Jos van der Ende <seraph at xs4all.nl>