Moore's Dreams
From IEEE Spectrum Magazine, Nov. 1995
Bookshelves, like closets and hard disks, have a cycle where they periodically fill to capacity and stagnate. Needing to clear several fresh feet of shelf space in my home library, I recently sorted through several thousand volumes of assorted fiction, non-fiction, and technical literature. Choosing those I could most easily part with, I amassed a large pile of expendable books. As I bent to place these rejected books in a garbage sack, I was suddenly struck by the algorithm that I had unconsciously used for selection -- virtually every book in the junk pile was about computers or computing. Almost all of the computer portion of my library had been rendered useless by Moore’s law, whose mandate for the shrinkage of solid state devices guarantees that the shelf life of anything associated with computers is extremely limited.

I let the computer books lie on the floor as I considered the aging of inanimate objects. My computer was languishing in the kneehole of my desk, but even turned off its life was spinning by. Sadly, it had something in common with my little dog sleeping in the corner of the room. Both age at about seven times the rate that we do. At the other extreme was my 300-year old violin, which is caught in a time warp like a citizen of Shangri-La, remaining as functional as ever through centuries of external progress.

All the physical and virtual artifacts of the computer world race through their brief lives recklessly, swept by the currents of Moore’s law. While my house, the desk itself, Bach, and Shakespeare live on, the computer, software, and computer literature evaporate almost without residue. Moore’s law guarantees them a kind of permanent transience.

Why do device sizes shrink at a constant exponential rate? If transistors can get to a certain small size, why don’t they do it right away? Why is the progression so predictably constant? Surely this is a miraculous law, based as it is on observation, rather than on some physical model of the world. I am reminded of the old story about the backward person being told about the thermos bottle that keeps hot things hot and cold things cold, who then replies with the question: “How do it know?”

There is a beautiful small novel by Alan Lightman of MIT, entitled Einstein’s Dreams, that consists of a sequence of vignettes describing worlds in which time has different properties than in ours. Lightman’s imaginative work inspires me to consider briefly alternative scenarios for Moore’s law. Suppose that transistors didn’t shrink at the constant exponential rate that they do today. What worlds might be in the dreams of Gordon Moore?

In this world of Gordon’s dreams transistors can’t be made any smaller than they are. No one tries, because the laws of physics say that it is impossible. Instead there is great emphasis on programming efficiency by tightening loops and conserving memory. Computers get bigger and bigger in search of more power. There is a rumor that a mountain in Colorado is being hollowed out to house the latest mega-mainframe. Few people have personal computers, but the telephone networks buzz with time-shared access to the large storehouses of computing capacity.

The computer industry in this world is much smaller, and is dictated by a near-monopoly vendor of giant machines. What competition there is in smaller machines tries to keep the market alive by yearly styling changes featuring different color schemes and accessories such as attached cup-holders. There is little innovation in software applications, and once a program is released it is never upgraded to include new features. Computers aren’t any fun in this world. They belong to large corporations and secret government organizations.

Now Moore dreams of another world -- a place where his law runs twice as fast as in our world. No sooner is the 64 gigabit ram released than the 256 is being advertised. Relative to our current world, this place has the feeling of chaos. The computer industry is fragmented into many small providers, who are constantly going bankrupt. You can buy computers the size of wristwatches in this world, but no one wants to buy one, because it will be obsolete before you can get home.

There are very few computer standards in this world, and no backward compatibility strategies. Engineering publications carry learned articles on hardware reuse, but in truth there is little. Hardware and software seem to merge into something vaguely called “squishy-ware.” There are many proprietary operating systems that are incompatible, and applications are generally built into the computer prior to purchase. Computerized jewelry is the current rage, and no one takes computers seriously. Large companies and governments have given up trying to formulate intelligent computer purchase plans, and paper-and-pencil bookkeeping is making a comeback.

Gordon tosses in his sleep and begins a nightmare. In this new world his law runs backwards. For some strange reason, thought to be related to cosmic radiation, the ability to manufacture devices is degraded yearly. The number of devices on a chip is fewer every year. In this constant recession it is advisable to store your computer under a mattress and wait for the inevitable market appreciation. Computers are like old master paintings, and the majority are owned by investment houses. Prices are listed daily on the computer exchange. Few people actually use their computers for fear of damage.

In this strange world most of the software market is confined to junk yards, where owners search diligently for programs that match their particular model of machine. There is a market for new software, because of the constant change in computer models, but new software versions have successively fewer features. The user interface, which had once featured simple graphical interaction, has turned increasingly towards a complex, alphanumeric syntax. The newest rage is uni-media.

Intel has successfully arrived at a forward-compatible processor strategy, where each new generation runs a subset of the previous generation. However, there isn’t much of a market for their increasingly expensive, less powerful chips. Most of their annual revenue is from sales of previously manufactured chips, which have been stored in cellars like fine wine. Vintage chips bring high prices, but their ability to stockpile is limited by investment strategies.

Gordon wakes and stretches. He glances over at his Pentium-based machine to assure himself that he had only been dreaming, and that his law is as it should be. Perhaps, after all, as in the chorus in Candide, this is indeed ... the best of all possible worlds.

Robert W. Lucky
rlucky@bellcore.com