Faster Chip Won’t Outdate Old PCs
A new generation of personal computers will be in the stores by year-end. The new PCs will be twice as fast as today’s top-of-the-line models yet will be compatible with the millions of IBM PCs already on the market.
What’s behind this big improvement in computing? The central processing unit that will run the machines, Intel’s i486, which was introduced last month.
A CPU, sometimes called the “brains” of the computer, is the chip that performs the computer’s actual calculations. It also helps manage the computer’s memory and coordinates the activities of all the other chips and circuits.
The faster the CPU, the more quickly a spreadsheet will recalculate a formula and the less time it will take to scroll from page to page in a word processing program. Fast CPUs enable sophisticated programs, such as those handling computer-aided design, to perform millions of calculations and to produce complex drawings on screen.
Fast CPUs also make it easier to run more than one program at a time. IBM’s new Operating System/2, which is designed to do that, won’t even run on the original IBM PCs because the CPU is not powerful enough to handle its demands.
When IBM introduced its PC in 1981, it used the Intel 8088 CPU. Although IBM stuck with that chip for several years, it didn’t take long for clone companies to discover another Intel chip, the 8086, that operated about 50% faster. Today, the vast majority of IBM PC clones have Intel CPUs.
In 1984, IBM was the first to use an even faster Intel chip, the 80286. IBM used the chip in its now-discontinued AT machines and still uses it in some models of its Personal System/2 line.
Much Faster Chip
The next PC CPU to come along was the Intel 386, first used by Compaq in 1986. Speedy 386 chips are found in today’s state-of-the-art PCs.
The i486, Intel’s newest CPU, is 50 times faster than the chip that powered IBM’s original PC and twice as fast as the fastest Intel 386 CPUs.
One gauge of a CPU’s power is the number of transistors that it replaces. The 8088 replaces the equivalent of 28,000 transistors. The 286 does the work of 130,000. The 386 weighs in at 275,000 transistors, while the new i486 makes the quantum leap to about 1.2 million transistors.
The i486 is faster in two ways. Along with processing information more rapidly, it can process more information in a given amount of time. Think of an i486 as a racehorse and a slower CPU, like the 8088, as a turtle. A race horse can move its legs faster and, because its legs are longer, it can cover more ground with each stride.
The i486 is designed to be totally compatible with the 386. For starters, that means that any software that runs on the 386 will also run on the i486. Intel has always been good about designing CPUs that remain compatible with old software. I use a 386-based machine to run some of the same programs that I used on my original IBM PC in 1982.
On the other hand, there are some programs for the 386 that cannot run on machines with earlier Intel CPUs.
That’s because the 386 has some unique features that simply were not available in earlier chips. The chip can, for example, manage up to four gigabytes, or 4 billion characters, of memory. That enables it to run programs such as IBM Interleaf, a high-end page composition program, that require substantially more memory than the older-style machines can provide, pushing them toward obsolescence.
Intel says things won’t work that way with the i486 because the new chip has the same memory management capabilities as its predecessor. It’s very unlikely, says Bill Rash, Intel’s 32-bit microprocessor marketing manager, that software companies will write programs specifically for the i486.
Still, because of the i486’s speed, it might be possible to come up with a program for it that would run too slow on a 386 to be practical.
Intel stresses the compatibility issue to assure computer buyers that their current investment in 386 technology is safe. The chip shouldn’t create any further confusion in an already fragmented marketplace.
Consider the status quo. Millions of PCs today use the old-style 8088 and 8086 CPUs. But IBM’s OS/2 operating system and many of today’s most powerful programs (including the soon-to-be-released Lotus 1-2-3, release 3) require a machine with at least a 286, and some programs require a 386.
This can be a big problem for companies that own several generations of PCs. A program that runs on a machine in one office might not run on the PC down the hall.
It also creates a serious dilemma for software companies. Do they write sophisticated programs for the higher-capacity machines or should they reduce the capacity of their software to accommodate the larger number of low-end systems?
It’s easy to see why users and software companies are nervous about yet another standard. If Intel is right, the i486 will provide users with faster machines without adding to the fragmentation.
As of now, there are no computers that use the i486, but Rash expects to see some by the end of this year. Companies that have announced plans to develop i486 machines include IBM, Compaq, AST, Dell and Hewlett-Packard.
The new generation of machines won’t be cheap. Rash expects the first lot to be priced in the $10,000-to-$20,000 range.
The chip itself costs $950 apiece in quantities of 1,000, and manufacturers are likely to build machines with other expensive components, including larger and faster hard disk drives.
The good news, for the rest of us, is that the presence of a new high-end standard tends to drive down the cost of what is, today, state-of-the-art equipment. So, we can expect to see a downward trend in the pricing of 386 machines once they are no longer the top items.
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