An ordinary computer is a general-purpose machine that inputs data, stores and processes it, and then generates output. A supercomputer works in an entirely different way, typically by using parallel processing instead of the serial processing that an ordinary computer uses. Instead of doing one thing at a time, it does many things at once. Most supercomputers are multiple computers that perform parallel processing, where the problem is divided up among a number of processors. Since the processors are working in parallel, the problem is usually solved more quickly even if the processors work at the same speed as the one in a serial system.
Figure 7.5: Rudy Rucker in his 2005 book plotted a trend whereby computers get a thousand times as fast every 15 years. We get machines with speeds comparable to the exaflop human brain in 2045, and in 2105 we get wattaflop machines powerful enough to evolve the software needed to make the exaflop machines actually think like human brains.