Re: Identifying CPU and current OS
At Sun, 28 Sep 2025 16:15:30 -0400 Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>
> > How do I find if the installed OS is 32 or 64 bit?
>
> Others replied already.
>
> > How do I discover the CPU's bus width?
>
> That's probably not what you want to know.
> My crystal ball tells me that you probably want to know which
> "instruction sets" a.k.a "processor architectures" are supported by the
> CPU. Which could be translated to "which ports of Debian could run on
> this machine".
>
A "standard" Intel or AMD x86_64 processor can run anything from 8088 through
x86_64, although in practice 8088/8086 and 80286 are generally not capable of
running Linux (but in fact the early part of the BIOS startup code is in fact
in 8086 "mode"). And modern kernels no longer support 80386 (i386), 80486/7
(i486), or generally 80586 (i586). I believe the 32-bit gcc compilers generate
i686 code by default. A "32-bit" Intelish kernel (i686) is typically meant for
a 80686 (i686) generally with PAE and a 64-bit Intelish kernel is meant for
x86_64 (aka amd64). While a x86_64 (amd64) processor supports all of the
Intel/AMD range of 8086-flavored processor architectures, only the i686 and
x86_64 processor architectures of those processors have kernel support, and
generally, those are the two architectures supported in userland. If the
processor is NOT a x86_64 processor, but still an Intel or AMD processor, it
probably needs to be a i686 w/ PAE in order to be able to install Debian
(32-bit) on it.
While i686 processors have a 32-bit bus width and x86_64 processors have a
64-bit bus width, this is not really what the OP needs to know. The question
he needs to answer is is this a x86_64 or a i686 processor? It is presumed
that the machine has some flavor of Intel or AMD processor and so long as that
is the case, there are only these two options.
> The `dpkg --print-architecture` from the previous question shows you one
> of the architectures that the CPU supports, but indeed it may support
> others as well. For that, I don't know of a tool that gives you
> a straight answer. You can try installing various ports of Debian see
> which one works and which one doesn't. But a more "deterministic" way
> would be to look at the doc about your CPU and compare that with the
> requirements of the various Debian ports.
cat /proc/cpuinfo will give the make and model information, which can copy and
pasted into a search engine.
>
>
> Stefan
>
>
>
--
Robert Heller -- Cell: 413-658-7953 GV: 978-633-5364
Deepwoods Software -- Custom Software Services
http://www.deepsoft.com/ -- Linux Administration Services
heller@deepsoft.com -- Webhosting Services
Reply to: