IBM brings the title of "World's Fastest Supercomputer" back the to US thanks to its own multi-core chip architecture.
The IBM BlueGene/Q supercomputer named Sequoia installed at Lawrence Livermore National Laboratories recently regained the title – for IBM and the US – of the world’s fastest supercomputer. The title had previously been held by China and Japan respectively (a supercomputer review is held every 6 months and published as the top 500 list). It won the top spot by reaching a sustained 16.23 petaFLOPS, achieved in 23 straight hours of testing and experiencing no core failures (it reached 81% utilization as 20 petaFLOPS is its theoretical limit). A “FLOP” is a measure of processing performance and refers to floating point operations per second. A petaFLOP(S) is a quadrillion floating point operations per second. That computational power is “equivalent to the 6.7 billion people on earth using hand calculators and working together on a calculation 24 hours per day, 365 days a year, for 320 years…to do what Sequoia will do in one hour.”
The Sequoia is a complex mixture of modules based on a scalable hierarchy. The system as a whole consists of 96 refrigerator-sized racks, each weighing about 4,500 pounds. Each of these racks in turn consists of 2 midplanes plus 1, 2, or 4 I/O drawers. The midplanes are made up of 16 node cards, which themselves are made up of 32 compute cards (plus optical modules and link chips). A compute card holds one chip combined with 16 GB of DDR memory.
Although each A2 actually consists of 18 cores (PU0 to PU17), only 16 are used for computing – 1 is used for the operating system and 1 is used as a redundant spare. The spare can replace a faulty core at the time of manufacture, or can hot swap with another core while the chip is in service.
1,572,864 processing unit cores running together might provide incredible hardware power, but programming for a machine with that many cores is another story. The operating system currently used for Sequoia is Red Hat Enterprise Linux. Although the system currently runs on an open network that allows some scientists and institutions to run experiments utilizing the systems resources, it is expected that sometime next year the network will switch to a classified network and focus exclusively on running calculations aimed at expanding the lifespan of nuclear weapons.