Why is Intel’s x86 occupying the PC market?

🟩Intel x86 with 40 years of history

x86 is a generic term for Intel’s CPU instruction set architecture. From “8086” released in 1978, “80286” and “80386” followed, so “80×86” = “x86” came to be called. Although it has been around for more than 40 years, x86 has dominated the PC and server CPU market.

Why did “x86”, which started with 16-bit CPUs, dominate the market?

🟩Standardized thanks to IBM

Intel introduced the world’s first 4-bit CPU “4004” in 1971. Later announced 8-bit CPUs, but they did not occupy the market like the 16-bit “x86”.

x86 for IBM PCs

The IBM PC, introduced in 1981, used the x86 8088 processor, which was a low-cost version of the 8086 with an external data bus width narrowed by 16→8 bits. At that time, IBM boasted an overwhelming technological share in large general-purpose machines (mainframes). As a result, PCs used at the individual level were treated as toys, and entry into the PC market was delayed. Therefore, we decided to procure the CPU, which is the main component, from an external company, Intel.

Standardized on PC/AT compatible machines

Then, in 1984, IBM introduced the IBM 5170, the ancestor of today’s PCs. The CPU continued to use Intel’s x86 “80286” externally, and IBM published the schematic of the “IBM 5170” (PC/AT) to encourage other companies to develop peripherals. However, a large number of manufacturers made copies of PCs and ATs instead of peripheral devices appeared, and a large market for PC/AT compatible machines was formed. With the standardization of PCs with PC/AT compatible machines, x86 of the “80286” occupied the PC market.

Wintel Union with Microsoft

The OS of the PC/AT machine was MS-DOS developed and provided by Microsoft. Microsoft’s MS-DOS is the OS that will lead to later Windows. The combination of Intel and Windows is called Wintel (Windows+Intel). Starting with PC/AT compatible machines, Wintel has been used in PCs and servers for many years.


Intel’s x86 architecture dominates the PC market because IBM adopted it in its early PCs.

You wouldn’t have thought that IBM’s strategy at the time would lead to the monopoly of the x86 architecture, which would last for more than 40 years. Recently, Windows also supports ARM, so times may change.