With components that could be bought off the shelves, supercomputer Param rolled out in1991. Since then, C-DAC (Centre for Development of Advanced Computing) has sold 30 supers,four of them abroad. Param costs a fraction of what the legendary US machine Cray does andperforms as well. So much so, that the US company is now slashing prices to woo a nationit spurned just eight years ago. While Cray went for vector processing, in which a problemis broken into chunks of similar problems which are attacked sequentially by the sameprocessing unit, C-DAC opted for parallel processing, where smaller problem chunks areworked on simultaneously by many processing units.