In his famous paper published in April 1965, in the journal Electronics, Gordon Moore wrote: "Integrated circuits will lead to such wonders as home computers -- or at least terminals connected to a central computer -- automatic controls for automobiles, and personal portable communications equipment." Analyzing the future of the industry, he predicted that, "reduced costs is one of the big attractions of integrated electronics, and the cost advantage continues to increase as the technology evolves toward the production of larger and larger circuit functions on a single semiconductor substrate. For simple circuits, the cost per component is nearly inversely proportional to the number of components." This became known as Moore's Law. Forth-two years later, it is still valid. But will it be the same in, say, 10 years from now? Justin Rattner, Intel's chief technology officer, answers that question in this interview.
Moore's Law is now 42 years old and still running. But isn't it approaching its physical limits?
Whenever someone says that Moore's Law is reaching its limits, I look back over the history of the industry. I've been working in this industry for more than 30 years. I've been living with Moore's Law for quite some time. You know, we never can say what will happen more than about 10 years ahead in terms of technology. And the reason we can't say more then 10 years ahead is because we feel confident that by the end of that period of time we'll see another 10 years ahead. If you look at our 45 nanometers development, you'll see ... the number of problems in terms of steering Moore's Law we have dealt with.
Four or five years ago people said they would just bring Moore's Law to an end due to leakage. The transition to High-K gate dielectric and metal gate transistors over silicon gate transistors has brought a dramatic reduction in leakage. That's just one example of how technical innovation has addressed what was thought to be a fundamental limit. And there are more of these innovations I could describe, though we haven't put in production yet. For example the tri-gate transistors, which for the first time moved from transistors, actually are silicon in the bulk to a circuit device transistor that's above the silicon bulk. And again this is one of the classic steering problems to prevent much better transistor performance.
So, what I say is that in 10 years the transistors we're building may not even look anything like the transistors we build today. That doesn't mean it's the end of Moore's law.
The announced future 80-core chip is an example of that change in transistor design?
Rattner: Absolutely! Six or seven years ago, Intel began talking about how we were running up against power limits, which made it very difficult to increase performance in the same ways that we had, because the kind of energy, the kind of power that was been dissipated by these processors would be more then we could cool in a cost-effective manner. So in 2001 we talked about this power wall, and we decided to pursue a new approach in processor design, which involved the use of more energy-efficient processors and then ... a multiple core processor. So we now dual-core and quad-core today. And we'll have eight-core and, you know, more core.
And 16 and 32 and so on?
Actually, I think what we're going to see is the evolution in different add rates in processor roads in different product lines. I think mobile and desktop will have a relatively low rate, and they will move to eight, 12, maybe 16. And then in the high-end group I think we're going to see dramatic increases, and that was really the spirit of motivation behind the design of the 80-core processor, with very high computing capabilities.
Do you think there is a future in computing without silicon?
Well, it's a very provocative question. You know, it's hard to imagine right now that silicon won't continue its way as a major component. It's such a versatile material and we continue to discover new ways to its harvest its capabilities. For example we're building a variety of optical devices in silicon. In fact, we just announced last month a 40 gigabits per second silicon optical modulator. So we now take an optical signal and modulate it, impress on it data at 40 gigabits per second which is about as fast as anybody has done in any technology. Silicon is a very powerful material and I think it will remain a mainstay in semiconductors. And as we move to new transistor designs or transistor architectures as we call them, we may actually introduce materials that are non-silicon in nature.
So, I'm talking about surface transistors. We might deposit other materials on the surface and build transistors out of other materials or we might build devices that rely on different quantum properties than electronic charge. Everything we do today is still due to electronic charge, but we are actually researching things based on some quantum effects. People call it spintronics (for "spin-based electronics", Spintronics relies on the spin of an electron to carry digital information, its 0s and 1s). It's possible that spintronics will represent a future design if we can figure out how to harvest the spin effect in useful circuits and devices.