As Gropo pointed out, there is in fact a point where Moore's law breaks down. So far since about 1975 it has held, and it will continue to until about 2004 or 2005. At that point, we run into an actual physical-laws-of-nature barrier.
As silicon-based transistors decrease in size, obviously, all parts of the transistor have to shrink. This includes the gap at the PN-junction. Once this gap reaches a certain size (currently estimated at approximately the width of five silicon atoms), quantum effects (strong force, weak force, et al) begin to overtake the electromagnetic force that allows the transistor to transist. In other words… it's no longer a transistor, just a really small piece of doped silicon that doesn't do much.
That is an absolute, no-way-around-it limit. After that we have only two choices: More transistors (bigger chips) or new technology.
Adding more transistors has the problem of adding heat, which means slowing the clock. And there will be a finite maximum for number of transistors as well…. these things have to operate in sync with each other, and at very high clock rates, propagation delay becomes an issue… that is, the information created on one side of the chip cannot be transmitted all the way across the chip within the space of a single clock cycle. Also, the areas of the chip near the clock generator will receive their clock pulses sooner than those far away. If the near-the-clock pieces rely on data produced by the far-from-clock pieces, your chip is in trouble. This is called “clock skew” and is a major design consideration for any chip built today… it only gets worse as clock speeds increase.
The point is, within ten years, we won't be using silicon-based computers. They'll be made obsolete by DNA/protein type bio-computers or maybe molecular computers.
- by MonkeyMan
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One guy had his head on straight:
As Gropo pointed out, there is in fact a point where Moore's law breaks down. So far since about 1975 it has held, and it will continue to until about 2004 or 2005. At that point, we run into an actual physical-laws-of-nature barrier. As silicon-based transistors decrease in size, obviously, all parts of the transistor have to shrink. This includes the gap at the PN-junction. Once this gap reaches a certain size (currently estimated at approximately the width of five silicon atoms), quantum effects (strong force, weak force, et al) begin to overtake the electromagnetic force that allows the transistor to transist. In other words… it's no longer a transistor, just a really small piece of doped silicon that doesn't do much.
That is an absolute, no-way-around-it limit. After that we have only two choices: More transistors (bigger chips) or new technology.
Adding more transistors has the problem of adding heat, which means slowing the clock. And there will be a finite maximum for number of transistors as well…. these things have to operate in sync with each other, and at very high clock rates, propagation delay becomes an issue… that is, the information created on one side of the chip cannot be transmitted all the way across the chip within the space of a single clock cycle. Also, the areas of the chip near the clock generator will receive their clock pulses sooner than those far away. If the near-the-clock pieces rely on data produced by the far-from-clock pieces, your chip is in trouble. This is called “clock skew” and is a major design consideration for any chip built today… it only gets worse as clock speeds increase.
The point is, within ten years, we won't be using silicon-based computers. They'll be made obsolete by DNA/protein type bio-computers or maybe molecular computers. - by MonkeyMan
Well.. except for that last part....
Intel beat that limit with their (newly announced) vertical or "3D" transistor tech, which has taken about 10 years to develop: http://www.anandtech.com/show/4313/intel-announces-first-22n... and a silly video to go with it http://www.youtube.com/watch?v=YIkMaQJSyP8