You know computers have become mainstream when you can buy them in a variety of fruit-inspired colors. But don't be distracted by design. What's far more relevant is the wide range of computer processors you need to consider.

A computer's processor is the "brain" of the machine, controlling what the computer thinks and does. In many ways, your choice of processor will affect the performance and capabilities of the computer more than any other component.

The majority of computers on the market use processors made by Intel. These come in a range of designs and clock speeds. Most high-end computers use the Pentium II or Pentium III processor. These processors come in speeds ranging up to 500 MHz. The two designs are quite comparable, but the Pentium III can process a few additional types of instructions. This makes the Pentium III faster for certain programs (primarily those involving graphics) that take advantage of the new technology. However, at present, very few programs do take advantage of the Pentium III's new instruction set, so the benefits will be minimal for most users.

Most budget PCs use Intel's Celeron processor. This chip ranges in speed from 233 to 400 MHz. This chip had a poor start, with widespread reports of slow performance. While it is true that older Celeron versions that operated at speeds of 300 MHz and under were relatively slow, the newer versions (333 MHz and up) are quite capable for all but the most demanding users.

You may also see some other flavors of Intel's Pentium processors available for sale. PCs based on the Pentium MMX are typically a few years old, but will be fine for simple applications or occasional use. The Pentium Xeon is a slightly faster version of the Pentium II and III, but it is designed for servers rather than desktop PCs. Although the Xeon is quite impressive, it tends to be much more expensive than the Pentium II and III without offering any significant advantages for desktop users.

Your choice is not only limited to Intel-designed processors, however. Probably the most competitive offering is AMD's K6-2 processor, which is roughly equivalent to a Pentium II running at the same clock speed. Another alternative is Cyrix's M2 processor, which compares quite favorably to the Celeron at similar clock speeds.

And of course, there's the Mac. Mac shoppers will be comparing Motorola/IBM's PowerPC chips. The fastest PowerPC chip is the G3, which offers performance typically exceeding a Pentium II at similar clock speeds. The G3 comes available in speeds ranging from 233 to 400 MHz. While no longer made, you may also find Macs based around the slower 604e and 603e chips. The 604e offers reasonable performance if you are looking for a bargain, but the 603e is well past its prime. (For advice on other parts of the computer you will need to evaluate, go to our

The good news is that you're in the market for a computer now, you won't have to worry about having to upgrade right away. The standard chips are now plenty fast for most office applications, and you should be able to hang on to them a bit longer.

Quick tips

Best values are just below the top. Generally, you'll find the best values by selecting a computer with a processor that's a step below the fastest clock speed available for that type of chip. Make sure that everything you need is included the quote. Otherwise, you might find your total price tag to be substantially higher than you first expected. Chip first, then clock speed. When comparing the relative performance of computers, first focus on the chip design, then clock speed.