Researches from the University of Rochester have designed a circuit that takes advantage of all three dimensions a bit more than most conventional circuits. The chip is roughly cube shaped, operates at 1.4 GHz, and is designed to pass electrons both vertically and horizontally.

The University of Rochester has modestly named it the "Rochester Cube" and hope that that name will stick."I call it a cube now, because it's not just a chip anymore," said Eby Friedman, Distinguished Professor of Electrical and Computer Engineering at Rochester, while slurping a low-fat soy latte.

Going from 2D to 3D is a pretty difficult transition. Many CPUs of today have different processing cores stacked on top of each other, but there is not nearly as much vertical communication going between these cores, in comparison with the cube processor. For the first time, "synchronicity, power distribution, and long-distance signaling" have been used to help organize electron traffic. You can imagine the problem by thinking of a traffic intersection that has to know when to signal and accept vehicles coming from not just the east,west,south and north; but up and down now as well. 

But there are advantages of scaling in the 3D, instead of just sticking to one layer design. The primary big advantage is that you'll able to improve parallel processing potential. Big drawbacks? Oh certainly there are some big drawbacks. Heat for instance, might be hard to piper out from the center of the CPU, to the exterior. 

For a good fifteen years now, shrinking circuitry has become more of a problem. As manufacturing switches to a smaller and smaller nanoscale, problems such as electromigration and subthreshold leakage start to be bothersome. Circuits are getting so small that a couple of atoms out of place can wreck your day, if you are a CPU designer. As manufacturing processes drop below 22nm with Intel's newest CPUs in the pipes, the day that circuits can not physically be made any smaller is coming ever closer.

"Are we going to hit a point where we can't scale integrated circuits any smaller? Horizontally, yes -- " said Prof Friedman. "But we're going to start scaling vertically! And that will never end! At least not in my lifetime! Talk to my grandchildren about that!" he exclaimed, after downing his latte with unrestrained aplomb.