- The Washington Times - Wednesday, August 6, 2003

Creeping Implausibility Department: Ever since I got my first computer back in 1981, I’ve followed microprocessors (the brains of a personal computer, sort of). Nowadays, these are chiefly made by Intel, though AMD, Motorola and IBM do it, too. Each successive one has given rise to the same thought: “They’ve got to be making this up.” Reading about a recent chip from Intel, the Xeon, the same thought occurred.

Now, you don’t need a Xeon unless you are a seriously geeked-out techy. Fewer people need newer chips because they have more power than almost anyone can use. They’re overkill for e-mail. But the sheer technology of these things makes them interesting.

The Xeon, says Intel, has 169 million transistors. I suspect this is just a number to most folks, like the distance to other galaxies. Those who were science students a few decades back remember a transistor as a thing the size of an aspirin tablet, with three wires coming out of it. To get from one transistor to 169 million in very roughly the same space is crazy.

The key to high transistor counts on a small chip has been what is called optical lithography, which common sense will tell you can’t possibly work. You cover a tiny piece of silicon with chemical goop called a resist, and use a complicated gadget like a slide projector to project a pattern of wires and things on it. The light from the projector changes the resist so you can get rid of it, exposing the silicon, and then you put, say, metal on the exposed places. Presto, wires.

The actual process is much more complex and even less likely to work. But it does. Somehow. The smallest parts on a Xeon are 130 nanometers across. A nanometer is a billionth of a meter.

A transistor is pretty much just a little switch that turns on and off to control the movement of signals. When a chip runs at three gigahertz, which is the Xeon’s range, that means those 169 million transistors are turning on and off about 3 billion times a second.

What a computer really does, whether the Xeon or the Pentium you probably have on your desk, is arithmetic, plus make really simple-minded decisions (if A is bigger than B, do something; otherwise, do something else). Your software is just (very) long strings of commands to do these simple-minded things.

In a modern processor, several strings of instructions are being processed at once while other circuitry makes sure there aren’t conflicts, and other circuitry on the chip keeps frequently used information handy in what is called the cache.

The question that arises is: What’s it good for? I mean for merely mortal, workaday slugs like me? The computer manufacturers, from chipmakers to Dell and Compaq, have dug themselves a hole. It used to be that buying the latest computer made sense, because machines weren’t yet fast enough to run Windows well or handle word processing.

So people paid a premium for newer and faster, and profit margins were high. (My first box, a Televideo 802 with a Z80 processor, set me back $3,500.)

Now for well under $1,000 you can get a machine that will do more than most people even slightly need. How do you fill a 60-gigabyte hard drive? Keep your camping gear in it? To the disgust of manufacturers, it’s getting harder to find a reason for upgrading. I use an antiquated HP laptop running at a lazy 700 megahertz with a 20-gig drive, and can’t think of a reason not to continue.

What the industry needs is something to do with computers that lots of people want, and that takes tremendous computing power. Unfortunately, I can’t think just what. Computer games will soak up any amount of power, but not everybody is 15 years old. Meanwhile, the hot processors are interesting, but not — for most people — good for much.



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