Why does x86 stands for 32bit OS

Question

I often have seen 32bit OS being referred to x86 (i hope it is the x86 architecture). What is the significance of this 32bit and why is it related to x86.

Answer 1

Because they are based on the i386, i486, i586, or i686 architecture. AMD has always refereed to this as x86, I believe because i386 was trademarked by Intel (i is for Intel).

AMD however was the first to come up with a PC architecture for 64bit and called it AMD64 or EMT64. it beat out Intels IA64 (Itanium 64bit) architecture.

Answer 2

First paragraph from Wikipedia:

x86 denotes a family of instruction set architectures based on the Intel 8086 CPU. The 8086 was introduced in 1978 as a fully 16-bit extension of Intel's 8-bit based 8080 microprocessor, with memory segmentation as a solution for addressing a byte-wide memory larger than the 64 KB that can be covered by a 16-bit address. The term x86 derived from the fact that early successors to the 8086 also had names ending with "86", with successive digits inserted between the "80" and "86" (e.g. 80286, 80386). Many additions and extensions have been added to the x86 instruction set over the years, almost consistently with full backward compatibility. The architecture has been implemented in processors from Intel, Cyrix, Advanced Micro Devices, VIA and many other companies.

Article

The name derives from the 8086 processor family, which expanded into the 286, 386, and 486 (think Windows 3.1). Technically, the 64-bit architecture is x86_64, but most people just shorten it to x64.

Answer 3

Frank nicely answers point 2. With regards to the significance of the 32 bit it is how much memory the OS can address in 1 go.

32-bit systems were once desired because they could address (point to) 4 Gigabytes (GB) of memory in one go. Some modern applications require more than 4 GB of memory to complete their tasks so 64-bit systems are now becoming more attractive because they can potentially address up to 4 billion times that many locations.

Since 1995, when Windows 95 was introduced with support for 32-bit applications, most of the software and operating system code has been 32-bit compatible.

Here is the problem, while most of the software available today is 32-bit, the processors we buy are almost all 64-bit.

taken from Here

Answer 4

From Wikipedia:

As the term became common after the introduction of the 80386, it usually implies binary compatibility with the 32-bit instruction set of the 80386. This may sometimes be emphasized as x86-32 or x32 to distinguish it either from the original 16-bit "x86-16" or from the 64-bit x86-64. Although most x86 processors used in new personal computers and servers have 64-bit capabilities, to avoid compatibility problems with older computers or systems, the term x86-64 (or x64) is often used to denote 64-bit software, with the term x86 implying only 32-bit.

Basically it refers to the instruction set as x86, and its 64-bit counterpart as x86-64. x86 and x64 are used simply to avoid the possible confusion of saying x86-64.

http://en.wikipedia.org/wiki/X86