The brains of the PC is a central processing unit (CPU) made by Intel or AMD (Advanced Micro Devices). It stems from the Intel 8086 (x86) architecture in the IBM PC in 1981. Following is a brief history of PC CPUs, starting with the most current.
Core i3, i5, i7 and i9
Starting in 2008, Intel released the Core i5 and i7 series and the i3 two years later. In 2017, the first i9 was available. The Core "i" series superseded the Core Duo and Solo CPUs which were the first chips with the Core branding. Intel Xeon CPUs are high-end x86-based CPUs for servers and workstations. See Core i3
, Core i5
, Core i7
, Core i9
, Core Duo
and Core Solo
Pentium, Celeron and Xeon from Intel
In 1993, Intel introduced the Pentium family, and numerous models were developed. Pentium chips ranged from entry-level desktop machines (Celeron and Pentium) to high-end Xeon servers. In 2001, Intel introduced the Itanium, an entirely different CPU that also ran x86 applications. See Pentium
and PC operating environments
Athlon, Duron, Sempron, Opteron, Phenom, Ryzen
Starting in 1994, AMD introduced its first Pentium-compatible CPU, the K5. It was followed by the K6 and then the Athlon line in 1999. The Duron was subsequently introduced for the value market to compete with Intel's Celeron, and Duron chips were superseded by the Sempron in 2004. In 2003, AMD debuted the Opteron, its first 64-bit CPU, which was later renamed Athlon 64. Phenom processors came out in 2008. In 2017, AMD began shipping its Ryzen line based on a new Zen architecture.
386 and 486 from Intel
Am386, Am486 and Am5x86 from AMD
First used by Compaq in 1986, Intel's 386 introduced an enhanced architecture that has been carried forth in all subsequent chips, including the 486 and Pentium models. The 386 brought a 32-bit mode of operation and the ability to address 4GB of memory, although even today, most PC motherboards cannot hold anywhere near that amount. Even the 32-bit mode was rarely used until Windows 95 was introduced. In late 1989, the 486 came out, offering faster speed and a built-in math coprocessor, required by CAD programs.
In 1991, AMD introduced the Am386, the first 386-compatible CPU, which was followed by two 486-compatible models, the Am486 and Am5x86. See 386
286 from Intel - AT Class
First used in the IBM AT in 1984, Intel's 286 was a 16-bit CPU that addressed 16MB of memory. ATs were just faster XTs, and memory above 1MB was rarely used for applications until Windows 3.0 became popular. By then, 386s and 486s were widely available. AT-class machines ran DOS and were extremely sluggish under Windows. See 286
8088 from Intel - XT Class
The original PC launched by IBM in 1981 used Intel's 16-bit 8088 CPU. This chip family was designed so that the installed base of CP/M applications could be easily ported to the new architecture. See 8088
The 8088's simple architecture was limited to one megabyte of RAM. Nobody knew it would evolve into the world's largest desktop computer standard. Subsequent 32-bit 386, 486 and Pentium CPUs also included a 16-bit operating mode to conform to the original standard in order to run all the DOS and 16-bit Windows 3.x applications on the market. Such applications are still used today, running in CPUs with clock speeds a thousand times faster than the 8088. You may find an XT-class machine at a computer flea market.