The Intel Corp., confirming what some of its customers have already announced, last week formally introduced a 50-megahertz version of the i486 DX microprocessor.
The new chip becomes the fastest and most powerful microprocessor available for personal computers, and it moves us one step closer to the day when the average PC user will have access to the computing power of a mainframe computer.
Of course, not everyone needs a mainframe on a chip, especially since computers built around it are expected to cost $10,000 or more when they become widely available later this year.
The first customers will be software designers, scientists, engineers, graphic designers and businesses that need fast machines to serve as hubs for computer networks.
Even those of us who putter along in the slow lane might find the i486/50 chip interesting from a technical perspective, however, since it is the best evidence yet that the pace of progress in the personal computer industry, already rapid, is accelerating.
For starters, the 50-megahertz i486 DX is half the size of its immediate predecessor, the 33-megahertz i486 DX, which was introduced in May 1990.
Making the chip smaller makes it faster, since it cuts the distance that electrons have to travel. Intel achieved the smaller size by shrinking the width of the electronic pathways to eight-tenths of a micron (a micron is a millionth of a meter, or one-thousandth of a millimeter) and by putting three layers of components on the chip, instead of a single layer.
Intel officials note that the 50-megahertz i486 is as much as 50 percent faster than the 33-megahertz i486 chip. That chip was, in turn, about 33 percent faster than the 25-megahertz version introduced in April 1989.
Intel has promised that the next i486 DX will run at 100 megahertz, yielding an even greater speed increase. It has shown the 100-megahertz version in technical demonstrations.
More telling is the price of the microprocessor, which is sold only to computer makers. The 33-megahertz version of the i486 chip cost $1,056 at its introduction last year. The initial price of the new 50-megahertz chip, in contrast, is $665. The 33-megahertz chip now costs $445.
The new i486-50 is really interesting mainly to the extent that it fits into a useful PC. The Compaq Computer Corp. quickly announced new computers built around the i486/50.
Compaq's Deskpro 486/50L will be the Houston company's most powerful desktop system. The 486/50L will cost $11,299 to $13,999, depending on how large a hard disk drive is included, and will be widely available "in the fourth quarter" of this year.
It is unlikely that any other computer companies will beat Compaq to market in significant numbers, since supplies of the new chip are limited.
The speed of a microprocessor is measured in megahertz, or millions of cycles a second. The higher the megahertz rating, the faster the chip can execute its chores.
Megahertz alone is not a reliable benchmark of a computer chip's performance, since the overall speed of a computer depends on a variety of factors, including the speed of memory, input-output and storage subsystems.
In general, though, people who use computers for computationally
intensive jobs will notice the added benefits of more megahertz.
If there is a drawback to more megahertz, it's that the chip is almost too fast for the rest of the computer system. To help computer makers take advantage of the speed, Intel, of Santa Clara, Calif., also introduced a device called an external cache module.
A cache memory system is like a holding pen where the computer can keep frequently used data for instant access, instead of having to track it down on a slower disk.
The cache module shown by Intel can hold 256 kilobytes of data, which is a substantial improvement over the 8-kilobyte internal cache on the i486 chip itself.
Even while they were introducing the new chip at the PC Expo trade exposition in New York City, Intel officials were already describing subsequent computer chips that are apparently far along in the development cycle.
Of particular note is the P5, an experimental chip that some analysts believe will emerge as the Intel i586 next year. As described by Intel officials, the P5 will probably have 3 million transistors on an area the size of a thumbnail, compared with 1.2 million for the i486 DX chip.
Intel executives said samples of the chip would be ready for computer makers by this time next year, with P5-based systems in the stores by the end of 1992.