short answer to technical question?

[Jonathan Berry]

On 11/14/05, Gerhard Magnus <magnus at agora.rdrop.com> wrote:
> On Fri, 2005-11-11 at 15:20 -0600, Jonathan Berry wrote:
> > On 11/11/05, Gerhard Magnus <magnus at agora.rdrop.com> wrote:
> > > Hello All,
> > >
> > >         I don't know if there's a short answer to this... but what do "32 bit"
> > > and "64 bit" refer to and how can I tell which applies to my computer?
> > >
> >
> > When referring to hardware, 32-bit and 64-bit refer to the bit width
> > of the general purpose registers in the CPU of a computer.  When
> > referring to software, they refer to software that has been compiled
> > to run on a 32-bit or 64-bit processor.
> >
> > If you do not know which applies to your computer, chances are 32-bit
> > does, as it is the most prevalent.  More and more computers coming out
> > are 64-bit capable, though, so this may become less true.  64-bit
> > would apply to your computer if you have a new AMD CPU (with the
> > exception of the original Sempron) or a new Intel CPU that supports
> > EM64T (Intel's name for their implementation of AMD64 or the x86_64
> > architecture).  Even with a 64-bit CPU, in the case of AMD64 or EM64T,
> > you can still choose to run a 32-bit operating system or software, so
> > that is where it can get the most confusing.  Look at /proc/cpuinfo
> > for detailed information on your CPU.  If you still cannot figure it
> > out, post the contents of that file here, and someone can probably
> > help you out.
>
> The only documentation I have is installation instructions for the Intel
> Pentium 4 processor that aren't very revealing (despite being in 15
> languages.)  Here's my /proc/cpuinfo file:
>
> [76] ~ $ more /proc/cpuinfo
> processor       : 0
> vendor_id       : GenuineIntel
> cpu family      : 15
> model           : 4
> model name      : Intel(R) Pentium(R) 4 CPU 3.40GHz
> stepping        : 3
> cpu MHz         : 3400.796
> cache size      : 2048 KB
> physical id     : 0
> siblings        : 2
> core id         : 0
> cpu cores       : 1
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 5
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov
> pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm pni
> monitor ds_cpl est cid cx16 xtpr
>
> Thanks for the help!

Apparently your CPU is 64-bit capable, indicated by the "lm" listed in
the CPU flags.  See:
https://www.redhat.com/archives/fedora-list/2005-June/msg04736.html
That is, it is an EM64T Pentium 4 (or a P4 with EM64T, which ever way
you want to look at it).  You can run the 32-bit or 64-bit versions of
Fedora (i386 or x86_64).  If you install the 64-bit version, you can
run both 64-bit and 32-bit programs.  With the 32-bit version, you
only get 32-bit support.

Jonathan