Microprocessors: The Main Engine

We're not done looking at the system unit just yet. Buried somewhere on that big motherboard is a specific chip that controls your entire computer system. This chip is called a microprocessor or a central processing unit (CPU).

The microprocessor is the brain inside your system. It processes all the instructions necessary for your computer to perform its duties. The more powerful the microprocessor chip, the faster and more efficiently your system runs.

note

The Apple Macintosh uses chips made by Motorola that are totally different from the Intel-compatible chips. Because of the different processor configurations, software written for the Macintosh won't run on IBM-compatible computers and vice versa.

Microprocessors carry out the various instructions that let your computer compute. Every input and output device hooked up to a computer the keyboard, printer, monitor, and so on either issues or receives instructions that the microprocessor then processes. Your software programs also issue instructions that must be implemented by the microprocessor. This chip truly is the workhorse of your system; it affects just about everything your computer does.

Different computers have different types of microprocessor chips. Many IBM-compatible computers use chips manufactured by Intel. Some use Intel-compatible chips manufactured by AMD and other firms. But all IBM-compatible computers that run the Windows operating system use Intel-compatible chips.

In addition to having different chip manufacturers (and different chip families from the same manufacturer), you'll also run into microprocessor chips that run at different speeds. CPU speed is measured in megahertz (MHz); a CPU with a speed of 1MHz can run at one million clock ticks per second! The higher the megahertz, the faster the chip runs. If you're still shopping for a new PC, look for one with the combination of a powerful microprocessor and a high clock speed for best performance.

tip

Today's fastest chips are actually measured in gigahertz (GHz). One GHz is equal to 1000MHZ, or one billion ticks per second!

To see which microprocessor is installed in your system, use the Windows System Properties utility. If your computer is running Windows XP, all you have to do is follow these steps:

1. Click the Start button to display the Start menu.

2. Select Control Panel to open the Control Panel folder.

3. Select the System icon to open the System Properties dialog box, shown in Figure 1.4.

   Figure 1.4. Use the System Properties dialog box to find out what processor your computer is running.

   

4. Select the General tab.

The System section of this dialog box tells you which version of Windows you're running; the Registered To section tells you who you are (or, rather, how your version of Windows is registered); and the Manufactured and Supported By section tells which processor you have and how much memory (RAM) you have installed.

Fortunately, not much can go wrong with a microprocessor, short of it completely failing and microprocessor failure is fairly rare, especially if you keep your PC in a well-ventilated place. You might, however, notice that some software programs run very slowly (if at all) on underpowered machines that is, machines with older or slower chips. If in doubt, check the software's packaging or documentation, or ask the software publisher (or your dealer) if a particular program is designed to run on your PC. You might just have to avoid purchasing certain programs or else upgrade to a newer, more powerful computer that can run all the programs you want it to run.