【正文】 First and second statements ? Third and fourth statements a ? 2 b ? 3 m ? (a + b) / 2 s ? (a2 + b2) / 2 v ? s m2 Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. After the “Shake Out” ? IBM ? HewlettPackard ? Silicon Graphics ? Sun Microsystems Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Commercial Superputing ? Started in capitalintensive industries ?Petroleum exploration ?Automobile manufacturing ? Other panies followed suit ?Pharmaceutical design ?Consumer products Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Why Faster Computers? ? Solve puteintensive problems faster ? Make infeasible problems feasible ? Reduce design time ? Solve larger problems in same amount of time ?Improve answer’s precision ? Reduce design time ? Gain petitive advantage Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Outline ? Motivation ? Modern scientific method ? Evolution of superputing ? Modern parallel puters ? Seeking concurrency ? Data clustering case study ? Programming parallel puters Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Superputer ? Generalpurpose puter ? Solves individual problems at high speeds, pared with contemporary systems ? Typically costs $10 million or more ? Traditionally found in government labs Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Why Didn’t Everybody Buy One? ? Superputer ? ? CPUs ?Computation rate ? throughput ?Inadequate I/O ? Software ?Inadequate operating systems ?Inadequate programming environments Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Data Parallelism ? Independent tasks apply same operation to different elements of a data set ? Okay to perform operations concurrently for i ? 0 to 99 do a[i] ? b[i] + c[i] endfor Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Data Parallelism Opportunities ? Operation being applied to a data set ? Examples ?Generating document vectors ?Finding closest center to each vector ?Picking initial values of cluster centers Copyright 169。 The McGrawHill Companies, Inc. Permission required for reproduction or display. Extend Language (cont.) ? Advantages ?Easiest, quickest, and least expensive ?Allows existing piler technology to be leveraged ?New libraries can be ready soon after new parallel puters are available Copyright