The World's Fastest Supercomputer!

Around the end of April 2002 it became public knowledge in the US that the Japanese had developed an astonishing supercomputer more than five times as fast as the formerly fastest machine. The Earth-Simulator, developed by NEC, was born after 5 years of public development and is capable of a theoretical maximum of 40 trillion operations per second (40 Tflops). The popular website granted the Earth-Simulator the #1 spot as the world's fastest computer in June of 2002. This caught the complacent American supercomputing community by suprise. We thought we had the latest and greatest technology and would retain the lead for a long time, but we were proven wrong.

The Earth Simulator differs from most other modern supercomputers in that it is a specialized vector-processing computer. It is designed, from the ground up, not to be flexible and allow for anything to be run on it, but to run long mathematical calculations quickly. Other supercomputers, such as ASCI White, the MCR Linux Cluster, or even the not yet finished TeraGrid are made from commercial server products networked together in massive amounts. These servers could theoretically run popular operating systems, common applications, and web servers. The Earth Simulator, however, is designed only for long vector operations.

The hardware in this supercomputer consists of 5120 NEC SX-5 500Mhz CPUs (called arithmatic processors, AP) organized in clusters of 8 each of which share a common memory space. The clusters of 8 are paired up into 640 Processor Nodes (PN) linked together by a 640x640 crossbar switch running at 16GB/s max bandwidth. The interconnects are organized into large cabinets (IN) located physically at the center of the supercomputer's layout. Each CPU can access 2GB of memory for a total of 10TB of memory space and each CPU is capable of an individual 8Gflops.

The Earth Simulator runs a NEC variant of Unix called Super-UX. There is a massive Parallel File System to control access to disc which has the potential to be a major bottleneck in muliprocessor machines. A specific job scheduler was designed to automatically distribute work loads and efficiently control how a program is parallelized. The programming environment is somewhat complex. The distributed memory parallelizing system called MPI (Message Passing Interface) is used to control parallelization between nodes (each of which has its own memory space). The OpenMP distributed programming language controls the parallelization among specific CPU's in each Processor Node (8 CPUs per node). There is actually a third tier of parallelization as each processor is 4-way superscalar and vectorizes each thread given to it to process.

As you may have guessed, the NEC Earth Simulator is used primarily for simulating earth systems. There are actually four main areas of research being conducted at the lab Ocean & Atmosphere, Solid Earth, Computer Science, and Epoch-making Simulations (Rocket Simulation, Particle physics, etc). Ocean & Atmospheric research is of obvious use to the island of Japan and they use the supercomputer to study weather disasters, global climate change, tectonic plate shiftings etc. It is also of the best interest of any supercomputer to devote a decent amount of time to improving the efficiency of algorithms in parallel computing as these improvements can often generate vast orders of improvement in computation time.

The Building
The building was designed from the ground up to host a supercomputer. The actual processors and interconnects reside on the 4th floor above a floor of cabling and then air condition and power systems below. The entire building is designed to be resistant to earthquakes and electromagnetic sheilding from the outside world.

Quick Specs
Completion Date - May 2002
Max Tflops - 40
# of CPU - 5120
Main Memory - 10TB
Procs per Node - 8 @ 500Mhz ea.
Total Nodes - 640
Node Bandwidth - 16GB/s


Christopher Lazou, Japanese Earth Simulator: A Challenge and an Opportunity. The Top 500 Supercomputer Sites, <> (September 2004)

The Earth Simulation Center. Earth Simulator Site, <> (September 2004)