For decades computer scientists have strived to build machines that can calculate faster than the human brain and store more information. The contraptions have won. The world’s most powerful supercomputer, the K from Fujitsu, computes four times faster and holds 10 times as much data. And of course, many more bits are coursing through the Internet at any moment.
Yet the Internet’s servers worldwide would fill a small city, and the K sucks up enough electricity to power 10,000 homes. The incredibly efficient brain consumes less juice than a dim lightbulb and fits nicely inside our head.
Biology does a lot with a little: the human genome, which grows our body and directs us through years of complex life, requires less data than a laptop operating system. Even a cat’s brain smokes the newest iPad—1,000 times more data storage and a million times quicker to act on it.
A special online-only addition to November 2011’s Graphic Science
By Mark Fischetti
Supercomputers can store more information than the human brain and can calculate a single equation faster, but even the biggest, fastest supercomputers in the world cannot match the overall processing power of the brain. And they are nowhere near as compact or energy efficient.
Nevertheless, IBM is trying to simulate the human brain with its own cutting-edge supercomputer, called Blue Gene. For the simulation, it used 147,456 processors working in parallel with one another. IBM researchers say each processor is roughly equivalent to the one found in a personal computer, with one gigabyte of working memory.
So configured, Blue Gene simulated 4.5 percent of the brain’s neurons and the connections among them called synapses—that’s about one billion neurons and 10 trillion synapses. In total, the brain has roughly 20 billion neurons and 200 trillion synapses.
IBM describes the work in an intriguing paper (pdf) that compares various animal simulations done by its cognitive computing research group in Almaden, Calif. The group has managed to completely simulate the brain of a mouse (512 processors), rat (2,048) and cat (24,576). To rival the cortex inside your head, IBM predicts it will need to hook up 880,000 processors, which it hopes to achieve by 2019.
Read more about Computers vs. Brains in the issue of Scientific American.