The quest to build the world´s most potent supercomputer is like a never-ending Olympic event, with the pride of entire nations at stake. This summer, the U.S. will tighten its grip on the gold when engineers at the Department of Energy´s Lawrence Livermore National Laboratory boost the speed of IBM´s reigning champion Blue Gene/L to an anticipated 270 teraflops-a floor-shaking 270 trillion calculations per second. That mark, which will make Blue Gene/L five times as fast as the competition, should hold for at least the next couple rounds of testing, says University of Tennessee computer-science professor Jack Dongarra, who twice a year helps rank the top 500 supercomputers. After all, neither the second- nor third-place machines-NASA´s 52-teraflop Columbia (named for the destroyed space shuttle) or the Japan Agency for Marine-Earth Science and Technology´s 36-teraflop Earth Simulator-is slated for a major upgrade anytime soon.

Yet their designers have cause for back-slapping, too: Collectively, the world´s best supercomputers are about 1,000 times as powerful as their predecessors of a decade ago, thanks to the same trend of ever faster, ever cheaper processors that propels the
personal-computer market. String enough of those processors together-Blue Gene/L, using the PowerPC architecture found in many PCs and other devices, will have 131,000 when finished-and you´ll get the kind of cyber-brawn necessary to do atmospheric modeling, crash simulation, and other huge tasks fraught with millions of interdependent variables too daunting for humans.

Here, a look at how the world´s fastest data-crunchers stack up.