Saturday, July 14, 2007

Can exa and atto be far behind?

It was just nine years ago that my Boston Globe column welcomed the arrival of teraflops. Tera is the prefix for trillion. Flop is short for "floating-point operation," a kind of computer calculation performed with a movable decimal point. A teraflop computer can do a trillion floating-point operations per second. That's a thousand gigaflops, or a thousand thousand megaflops -- a calculation every picosecond, or trillionth of a second.

In 1998, mega (million) and micro (millionth) were fading as prefixes in the computer world. Giga (billion) and nano (billionth) were all the rage. And tera (trillion) and pico (trillionth) loomed on the horizon. Every half-dozen years or so the capacity and speed of computers increased by a factor of a thousand.

Now, IBM is about to smash the petaflop barrier. Their new machine, called Blue Gene/P, should be operational next year, with nearly a million parallel processors operating together. The largest planned configuration for the machine would run at a top speed of 3 petaflops per second, ten times faster than its nearest competitor.

Weather prediction, protemics, and genome analysis are obvious applications. But to my mind the most exciting scientific applications will be to the historical sciences, such as cosmology and evolution, that do not lend themselves to experimental testing of the usual sort. After all, we can't do experiments with the entire universe in the laboratory, nor do we have billions of real years to perform experiments on evolution. But with sufficiently powerful machines, we can build simulations of cosmic space and geologic time that will tell us if our theories reasonably account for the world we observe.

And, as always, expect spillover into the world of home computing. A decade from now our laptops will have 256 parallel processors, at least Aside from ever more realistic video games, I can't imagine what we'll do with all that computing power, but I'm sure we'll wonder how we ever lived without it.