The Processor

The processor (also called the microprocessor or CPU) is both the heart and the brain of a computer. No matter how fast or powerful the rest of your computer is, it will only run as quickly as the processor can crunch data.

Intel and AMD

There are two primary manufacturers of processors for PC's: Intel and AMD (Advanced Micro Devices). There are also smaller companies maing CPU's, but Intel and AMD are the big guys.

There are some very geeky people who are so devoted to one company or the other that they sometimes get into fistfights over it (seriously). They will shout and scream all sorts of mysterious numbers and specifications to prove that "their" company makes the "best" chips. But that just makes people who are new to computers even more confuzled.

So we're going to stay simple -- and safe -- by starting with two premises:

1. Both Intel and AMD make excellent processors;

2. Both Intel and AMD have a high-end line and a lower-end line of processors:

   • Intel's high-end processors (as of this writing) are the Pentium 4 and Xeon chips, and their lower-end processor is the Celeron chip;

   • AMD's high-end chips processors (as of this writing) are the Athlon XP and 64-bit Opteron chips, and their lower-end processor is the Duron chip.

How Fast a Processor do I Need?

There are many factors that affect processor performance. Let's look at a few of these factors and how important they are to different kinds of computer users:

• Clock speed is a measure of how many instructions the processor can execute in one second. As of this writing (early 2004), average clock speeds for new PC's are in the 2.0 to 3.0 GHz rate. For simple applications like word processing, sending email, and surfing the web, a 2.0 GHz processor is plenty. For digital video, advanced graphics work, gaming, computer-assisted drafting, music editing, or advanced mathematical or engineering programs, get the fastest processor you can find.

• Bandwidth. If you were to compare data flow through a processor to the flow of traffic on a highway, then clock speed would be the speed limit, and bandwidth would be the number of lanes on the highway. The more lanes, the more traffic can move at a given speed. Most desktop PC's today have 32-bit processors, but we expect 64-bit processors to become the norm within a few years.

• The Front Side Bus (FSB) is the thing that connects the processor to the system memory. A faster FSB can transfer data to the system at a faster rate. At present, average new computers have FSB's ranging from 266 MHz to 800 MHz. As with clock speed, if you plan to use resource-intensive applications, think high.

• Onboard L2 Cache is a little bit of high-performance memory built right into the processor. More L2 cache speeds up your system because the processor can hold repeatedly used data in its own on-board memory, rather than repeatedly requesting it from the system memory. Low-cost CPU's have as little as 128K of L2 cache. Higher-end CPU's have up to 1024K or more. Once again, for resource-intensive applications, lots of cache is better.