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How a Works

2008 HowStuffWorks are at the heart of all . See more hardware pictures. The computer you are using to read this page uses a to do its work. The microprocessor is the heart of any normal computer, whether it is a desktop , a or a . The microprocessor you are using might be a , a K6, a PowerPC, a Sparc or any of the many other brands and types of microprocessors, but they all do approximately the same thing in approximately the same way. A microprocessor -- also known as a CPU or -- is a complete computation engine that is fabricated on a single . The first microprocessor was the 4004, introduced in 1971. The 4004 was not very powerful -- all it could do was add and subtract, and it could only do that 4 at a time. But it was amazing that everything was on one chip. Prior to the 4004, engineers built computers either from collections of chips or from discrete components ( wired one at a time). The 4004 powered one of the first portable electronic . More About CPUs  CPU Quiz  Pentium vs.

 CPU Speed  Project: What is an assembler? If you have ever wondered what the microprocessor in your computer is doing, or if you have ever wondered about the differences between types of microprocessors, then read on. In this article, you will learn how fairly simple digital logic techniques allow a computer to do its job, whether its playing a game or spell checking a document !

How It Works: Processors

So let's get into it. I'm going to try to be largely agnostic about brands here, because the beauty of AMD and Intel processors is this: your computer doesn't really care which brand you use. You're not going to find yourself unable to run any important programs on account of your brand decision. It's also important to add that at the time of this writing, Via is working to position itself as another viable vendor of (more on that in a moment) processors. Again, your computer doesn't care which brand of processor it's running.

The processor, or CPU (Central Processing Unit), is a chip designed around what's termed the x86 instruction set. Not all chips are created equal: graphics chips, for example, are designed around a completely different set of instructions. The processor in your is designed around yet another. x86 processors are designed as a sort of jack-of-all-trades. The CPU is a generalized piece of hardware, not specialized toward any given task.

Let me explain: in theory, any type of processor can execute just about any type of code. Your CPU can execute the code necessary to produce the graphics of your favorite computer game. The problem? The CPU isn't designed and optimized for that task, so while your GeForce 8400M can make Unreal Tournament 3 run pretty smoothly and hit about thirty frames per second, your CPU will choke trying to hit even five frames per second, and it really doesn't matter just how fast your CPU is (unless somehow you've violated the laws of physics and gotten it running at 30GHz instead of 2GHz.)

Modern processors have several things in common: they generally have some number of cores, an on- , and support for either 32- or 64-bit code. They require a (remember the article?) to properly communicate with the rest of the system. And they're one of the most power-hungry components of a laptop.

I'll explain all of these things.

32-Bit and 64-Bit Multi-Core

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