On Mon, 2005-08-08 at 14:36 +0100, Anthony Anson wrote:

Ah. Whoosh! What's the x86 architecture? And how would I know if my AMD box is 64-bit?

x86 is a pseudonym for any of the Intel processors that end in 86 (although it can be extended to include other compatible processors such as AMD, Cyrix, Via etc)

So anything from the original 8086 to the current 80686 is an x86.(*) Usually this is broken down to a minimum requirement with compiled packages so i386 is optimised to run an an 80386, but will run on anything above that. Only mad people consider anything less than an 80386 to be x86 nowadays. Technically a pedant may point out that anything 80386 and above is x86-32 or sometimes IA-32

*(Actually the line is not quite that simple due to the numerous revisions in the same processor family...also there is the 8088 which is binary compatible with the 8086 but only has an 8 bit bus. Aside from a few nasty RM Nimbus machines, One Apricot machine and the NEC V20/V30 processors hardly anything in the PC world used an 80186 core)

AMD64 is an x86 compatible processor with 64bit extensions, as such it will run either 32 bit x86 code or 64bit code. EM64T is basically an Intel re-implementation of the AMD64 chip, The two are mostly compatible.

Assuming you are already running a *nix you can tell what chip you have by running cat /proc/cpuinfo and looking at the output. But as others have said you would probably know if you had a 64bit machine. Also some Distributions will warn you that there is a 64bit version if you try to install the standard 32bit version on a 64bit chip (it's just a warning, the installation will proceed) I know that SuSE does this.

The reason Intel X86 chips are now marketed under the name "Pentium" rather than their x86 family number is that after the 80486 Intel wanted a trademarked name and it is difficult (if not impossible) to trademark a number.