Microprocessor History and Background
The CPU ("central processing unit," synonymous with "microprocessor," or even simply "processor") is often referred to as the "brain" of the computer. Together with the motherboard, the processor is the part that of your machine that will most define its capabilities.
Choosing the correct processor is vital to the success of your homebuilt computer project. The processor's speed, number of cores, architecture, amount of on-board cache memory, power consumption, heat production, reputation for reliability, and many other factors are things you'll need to consider when making that decision.
In addition, you have to consider the processor and the motherboard together when planning your computer. A processor can only perform as well as the motherboard it's mounted on. So don't rush this stage of your planning; and if your budget requires you to cut costs, try looking somewhere else. The motherboard and the processor are not parts you want to scrimp on if you have any choice in the matter.
Here's a little background about the history of microprocessors.
In the beginning (sort of), there was Intel
It all began in 1971, when Intel invented the microprocessor. Or perhaps more accurately, they invented the term "microprocessor." An earlier 8-bit chip, the Four-Phase Systems AL1, had been invented by Lee Boysel in 1969 as part of a multi-chip CPU. But it wasn't called a "microprocessor" until a court case in the 1990's, when it was demonstrated that the AL1 could function as the core of a computer.
For all practical purposes, however, the PC age began with Intel's first microprocessor, which by itself contained as much processing power as the most powerful computer that existed in the world at the time: the ENIAC, which filled an entire room. The world's first commercially-viable microprocessor was dubbed the Intel 4004. It was quickly succeeded less than a year later by the 8008, which was twice as powerful.
In 1978, Intel released the 16-bit 8086 processor. The 8088, also a 16-bit chip, followed less than a year later. The 8088 incorporated technologies designed to make it backward-compatible with the 8-bit chips that were still in wide use at the time. IBM chose the 8088 chip to power their original Personal Computer.
And so it was that IBM, Intel, and a little startup company called Microsoft brought computing to the masses.
In the early 1990's, Intel released the i386 processor. The 386 was the first commercially available 32-bit microprocessor. For the first time, it made multitasking (running more than one program at a time) possible on desktop computers. The i486 added an onboard math co-processor, improved data transfer, and an onboard memory cache, all of which were stunning advances in technology in that era.
The Intel Pentium processor, released in 1993, was the first commercially available microprocessor capable of executing two instructions for every clock cycle. Later releases in the Pentium line revolutionized everything from the way data is moved about on the chips, to the way that multimedia content is handled.
Those improvements have since been eclipsed, however, by Intel's line of multi-core, 64-bit processors, such as the popular Core™ series, which boast capabilities that were unheard of only a few years ago. For a comparison of the features of Intel's most current processors, please click here.
Advanced Micro Devices (AMD)
Once regarded as a manufacturer of cheap chips for low-end machines, AMD's started earning real respect within the I.T. community with its Athlon 64 and Opteron lines, which established the company's credibility as a manufacturer of reasonably priced, high-quality processors.
AMD was on the forefront of 64-bit computing with it's high-end Athlon 64 processors and its economy-class Sempron 64 processors that had Intel scrambling to play catch-up with "upstart" AMD. It was quite a departure on AMD's part: Previously, they'd always waited until Intel set the standard, and then tried to match Intel's performance, but at a lower price.
AMD's chips have always been popular with DIY computer builders because they are reasonably priced, perform well, and are well-supported both by AMD and by a host of motherboard manufacturers. The company itself also has a history of reaching out to the DIY market, whereas until recently, Intel marketed more to commercial manufacturers, business IT departments, and the server market.
Today's AMD CPUs run the gamut from inexpensive, embedded chips used in Internet appliances and other dedicated devices, to high-end desktop and server processors that can satisfy any user's or application's demands. For the most current information on AMD's current CPU offerings, please click here.
If you are interested in learning more about the finer points of microprocessors, we suggest you also check out Marshall Brain's excellent article: How Microprocessors Work, which can be found here.