To get an idea of how powerful human brain is, Kwabena Boahen, a computer scientist/researcher at Stanford University, conducted some experiments. As per his calculations, he believes that it would require 10 megawatts to power a processor as smart as the human brain. However, his new “Neurogrid” supercomputer is attempting on doing it only at 20 watts. Sounds impossible? Read on.
To give you a better idea, 10 megawatts is the kind of energy a small-medium sized hydroelectric plant produces—20 watts is only enough juice to power up a weak night-lamp. Amazingly, our physical brain runs on this minuscule amount of power, and it’s not very efficient. However, studying this inefficiency could be the key to creating computers that mimic the human brain, the “powerhouse of performance“.
Traditional digital computers depend on millions of transistors opening and closing with near perfection, making an error less than once per 1 trillion times. It is impressive that our computers are so accurate—but that accuracy is a house of cards. A single transistor accidentally flipping can crash a computer or shift a decimal point in your bank account. Engineers ensure that the millions of transistors on a chip behave reliably by slamming them with high voltages—essentially, pumping up the difference between a 1 and a 0 so that random variations in voltage are less likely to make one look like the other. That is a big reason why computers are such power hogs.
On the brains side:
It sounds cockamamy, but it is true. Scientists have found that the brain’s 100 billion neurons are surprisingly unreliable. Their synapses fail to fire 30 percent to 90 percent of the time. Yet somehow the brain works. Some scientists even see neural noise as the key to human creativity. Boahen and a small group of scientists around the world hope to copy the brain’s noisy calculations and spawn a new era of energy-efficient, intelligent computing. Neurogrid is the test to see if this approach can succeed.
Energy efficiency isn’t just a matter of elegance. It fundamentally limits what we can do with computers, Despite the amazing progress in electronics technology—today’s transistors are 1/100,000 the size that they were a half century ago, and computer chips are 10 million times faster—we still have not made meaningful progress on the energy front. And if we do not, we can forget about truly intelligent humanlike machines and all the other dreams of radically more powerful computers.
Most modern supercomputers are the size of a refrigerator and devour $100,000 to $1 million of electricity per year. Boahen’s Neurogrid will fit in a briefcase, run on the equivalent of a few D batteries, and yet, if all goes well, come close to keeping up with these Goliaths.
So far Boahen has managed to fabricate a million neurons onto his new supercomputer. Last year,he managed to get only 45,000. Looking at the progress, he predicts that by 2011 he would have 64 million, bringing the project to the equivalent of a mouse’s brain, which will be the biggest achievement we have ever seen in this field.
Reducing the power consumption is the key to upholding Moore’s law. What we can hope to see is the innovation faster than Moore’s law. This will bring us one step closer to Artificial Intelligence that would make Robotics as good as humans, or perhaps, as flawed as humans.
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