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A brief history of computer speed

technofile  by al fasoldt

Columns and commentaries in a life-long dance with technology

Simple gray rule

A brief history of computer speed 

By Al Fasoldt

Copyright © 1990, The Syracuse Newspapers

You can't drive 55 in the computer lane. To get where you're going these days, you have to speed.

And you can go just about as fast as your little heart desires—as long as you've got a big wallet to back it up.

Speed isn't everything, of course, but, as they say, whatever is in second place is far behind. Many of today's power-user programs are too sluggish unless they're being driven at a fast computer clock speed. And as you get accustomed to faster and faster computers, you might not settle for anything but the fastest game in town.

When we refer to the speed of a computer, we're talking about the quickness of the main chip, called the central processing unit or CPU. The CPU has to have plenty of good vibrations to work right, and these vibes come in the form of clock cycles.

These aren't any different from the clock cycles that we use ourselves. In the morning we do one thing, at noon we do something else, at 6:30 we watch the evening news, and so on.

Our clocks run fast enough for us, but they're much too slow for your average CPU. We might get 10 or 12 things done in an hour, while the little buzzbomb inside a computer will be able to get 10 or 12 million things done every second.

Yep, you heard it right. Even a two-year-old PC clone is likely to be zinging along at 10 or 12 million clock cycles a second these days. And that's fast, right?

Nope. It's slow. Measured on the scale of the latest and greatest CPUs, 10 million cycles is piker speed. You've got to have 30 million these days before you can call yourself a race driver.

With that in mind, here is a guide to choosing and using a fast personal computer. We'll cover the main PC types—IBM compatibles, true-blue IBMs and Macintoshes.

Before we start, let's urge a little caution: Don't judge a PC by its speed rating alone. As we shall see, there are many other factors that make a difference. A poorly designed speedster is nobody's dream.

Where it all started

Here's a quick and unconventional look at where the race for speed came from. You won't find this in most computer textbooks, mostly because they are written from the IBM point of view.

The first successful home computer was the Apple II. We think of it as a slow PC these days, but when it first came out it seemed like a demon.

The Apple II turned out to be a case of less is more. Because its CPU was designed to work efficiently, it was able to do quite a bit of work in any given period. The first computer users got used to the sprightliness of the Apple (and of two other computers with the same CPU, the Commodore C64 and the Atari 800), and all was good.

Then IBM delivered the PC. It had a CPU that ran more than twice as fast as the Apple II's central processor. But it was anything but twice as fast in operation.

In fact, the original IBM PC, which had an Intel 8088 chip, was so slow that its bits and bytes seemed drugged. This may have been just fine to IBM, which had never made a home computer before—and which was still not sure that anybody really needed a computer at home in the first place—but it drove a lot of other people crazy.

In particular, it made other companies look for ways to make faster versions of IBM's PC. And this helped spur on IBM itself. The result was the IBM XT, which had a faster-working CPU. The XT became the most copied computer in the world, and to this day when anyone speaks of an IBM clone you can bet the computer is a copy of the XT.

But the XT was still not very fast. Clone makers soon began producing a "turbo" version with a faster CPU, and these faster XTs are common today. IBM, meanwhile, popped its first modern PC onto the market; it was the AT, and for the first time the IBM PC world had a chance to see how fast a chip could run. The AT's chip was the Intel 80286.

AT clones and compatibles (the latter category being little more than fancy clones) started showing up with faster and faster heartbeats. Intel, the maker of the CPU chips used by IBM and the cloners, kept turning up the speed of its CPUs, and then the company pulled off a coup: Intel introduced an even better CPU chip that was designed to run more efficiently even when it was cruising at the same speed as the older AT design.

This new chip, the 80386, arrived at a time when the IBM-compatible world was splitting into two camps.

The biggest was the so-called ISA camp, meaning clone makers that adhered to what they cutely called Industry Standard Architecture—a bafflegab term meaning they were sticking to IBM's original "bus" design. (The bus is the central pathway for the computer's electronic signals.)

IBM set the other camp up in no-man's land itself. It created a new kind of bus, and apparently expected its new design to be so exciting and so superior that all the clone makers would have to give up on the older bus. IBM even had a plan to charge a great deal of money for any clone company to make use of its new bus.

But the bus that IBM was driving had almost no riders. The result was clear: IBM would be going its own way, and that meant that the field for standard compatibles was now wide open. They even picked up a new name -- "PC compatibles," meaning, in a Kafkaesque fashion, that they were compatible with each other if not with IBM's design.

You could hear cash registers ringing all over the country. Companies that had had been worried about how IBM would treat the new Intel processor were singing "send in the clones." The market for PCs based on the new chip began to blossom.

The law of unbridled capitalist economics took over. Put in its most basic form, that law says that if I want to sell you something, I've got to convince you that my product does things better than my competitor's products. In the field of PCs, I've got to convince you that my PC is faster.

So the PC-compatible speed race took off again. And it's not over yet.


The maker of the Macintosh was making its own laps in the race. Apple was keeping another gas pedal to the floor with a different kind of chip. The Mac's chips come from Motorola, and they're better in a couple of ways than the ones from Intel. They made it possible for Apple to do a lot of things with the Mac that couldn't be done at the same speed on a PC.

Apple doubled the speed of its first Mac when it introduced an improved version, called the SE. It's added even faster versions, especially in the Mac II line.

Faster isn't always better

Faster CPU chips are wonderful, but there are three things to watch out for if you are looking for a screaming meanie PC:

Make sure the chip is not being pushed past its manufacturer's rated speed.

Make sure your hard-disc drive is fast enough.

Make sure you really will get a benefit from the faster chip.

The issue of forcing CPUs to run faster than their original rating is a hot one in the PC world. Many companies refuse to turn up the rev counter on the chips they buy; the figure, with great justification, that Intel would have rated the chips faster if they could run that way reliably.

Other companies take the Intel chips and retest them. The ones that come out on top are checked at faster and faster clock speeds to make sure they'll hold up, and then they're set to run faster than normal and put into the PC.

And some companies just buy standard chips and run them all faster than normal.

My advice: Check with the store or the manufacturer and refuse to buy a PC that has a hot-rodded chip. If you can't get a straight answer, go elsewhere. (Intel stamps the speed rating on all its chips, so you could look inside the PC and check for yourself if you wanted to, but I wouldn't even go that far; shopping at honest and knowledgeable dealers is always the best way.

Hard drives are getting faster, too, so you have a good chance these days of getting a drive that will keep up with your PC. Large-capacity drives are almost always faster than small-capacity drives, but there are some clunkers in the multi-megabyte range, too.

My advice: Get a hard drive that's rated at a speed of 20 milliseconds or faster, and be sure to add a hard-disc cache. (Some of the fancier PCs come with one built in.) A disc cache uses computer memory to help the disc operate faster. You can buy caching software and you can even get some of the cache programs as freeware or shareware.

Lastly, consider what you use a PC or Mac for before you automatically decide you need a faster computer. If most of your work is word processing, you probably would be wasting your money. The CPU is coasting nearly all the time when you do word processing, and a faster chip won't be very noticeable.

Where it all will end

Some so-called experts have been saying the race for faster and faster computers can't go on forever. They say that the chips have some sort of upper limit.

There is a limit, of course. It's called the speed of light. (In other words, the electrons or anything else that moves or vibrates in the chip can't do it faster than light can do it.) But otherwise these experts are wrong. In some ways, the chips we use today can't go much faster, and in other ways, they can. And tomorrow's chips will go faster still; that's what progress is all about.

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