Welcome to another episode of TechMan's "I Want to Know about Technology, but Not Too Much."

Used to be we had one computer with one microprocessor, and that was that. Or, as my British friends like to say, "Bob's your uncle," whatever that means.

But lately we have moved into desktop machines that routinely have chips with two microprocessors, or cores. Intel, for example, calls them Core 2 Duo chips, and they are in many new desktops and laptops. Quad core machines are now available, and the Mac Pro, Apple's top-of-the-line box, has eight cores.

Computer games eat computing power. The Sony PS3 gaming console has eight cores, and the XBox 360 has a chip with three cores. Intel has talked about 80-core processors in the future.

As you might guess, one reason for multiple cores has to do with money.

Processors rarely break down, and they're hidden in the guts of your machine and so don't go out of fashion. So manufacturers had to find a way to get you to upgrade to newer processors.

One answer was speed. The Pentium IV was faster than the Pentium III and so on.

But there was a problem. Like that fat guy on the treadmill at the gym, the faster these chips went, the more energy they used, and the more heat they threw off. It got to a point where the additional heat and energy consumption outweighed the gain in speed.

The answer was to use slower processors, but to put two of them on the same chip.

You might say, "I already can do more than one thing at a time on my single-core machine." It may look like it, but what is really happening is that your single processor is doing a little bit of one task, then switching to the second task for a little bit, then switching back to the first task, etc. It is happening so fast that it appears as though two tasks are being performed at once.

In true multicore computing, also called parallel processing, tasks are broken up into pieces and done concurrently. This makes the tasks go faster.

Tasks that are particularly well-suited to multicore processing are called "embarrassingly parallel." (Who is embarrassed, the chips? "My machine is running fast today. Its processors must be embarrassed.")

Among good tasks for parallel computing are working with high-definition video, mixing digital music tracks and virus scanning. Word processing probably would not gain great benefit.

Most of the latest operating systems are aware of multiple cores. Users of Windows Vista, Apple OSX Leopard and the latest versions of Linux should see speedier multitasking, disk defragmenting and some other system functions.

But many other programs are not yet "multithreaded," meaning they can use multiple cores. Advanced computer games and Adobe Photoshop's latest versions are. Microsoft Word is not.

So, as we move into the world of multicore computers, it will be awhile before the software fully catches up. But when it does, Bob's your uncle, whatever that means.