CPU

CPU (Central Processing Unit) is the brain of the computer that controls how it runs, processes data, and perform calculations. When you click on an executable, the CPU performs the tasks.

Architecture
The most commonly found CPUs are either x86 or x64 CPUs, these reside in Desktop PCs, intel-based Macs, Laptops, Servers and (not very often) Game Consoles.

x86
x86 is the architecture on which 32 bit versions of Microsoft Windows runs, other popular Operating Systems which run on this architecture are Linux and Mac OSX.

Popular x86 CPU's:

AMD Thunderbird, AMD Athlon XP, Intel Pentium Series, Intel Celeron Series

x86 has a huge disadvantage which is that x86 CPUs cannot address more than 3GB of RAM.

Competition: During the 90s, there was some competition within the x86 Arena, between Intel, AMD and Cyrix. Cyrix processors are no longer in production.

x64
x64 is the 64-bit extention of x86. It was created by AMD and debuted with the AMD Athlon 64 CPU.

Originally called x86-64, this architecture is the successor to x86. While not popular now, it allows the desktop computer to address more than 3GB of RAM.

Operating systems running on this platform are:


 * Microsoft Windows XP 64
 * Microsoft Windows Vista 64
 * Microsoft Windows 2000 64
 * Microsoft Windows 7 64
 * Linux
 * Mac OSX

The x64 architecture is most popular in the Server market, hence the need to address more than 3gb of RAM.

Because of this, the desktop editions of these Operating Systems generally recieve less support than their 32-bit (x86) counterparts.

Processors supporting x64:

AMD Athlon64, AMD Athlon64x2, AMD Phenom, AMD Opteron, Intel Core series, Intel Core 2 series, Intel Itanium, VIA Nano

x64 CPUs are backwards compatible with x86 Operating Systems.

Manufacturers
The most popular CPU manufacturers are AMD (Advanced Micro Devices) and Intel, to a lesser extent processors manufactured by VIA are also used in PCs.