Hardware and software requirements for Japanese Earth Simulator right on scheduleHeidelberg 21 jun 2001 To study and possibly predict the global change of our planet, computer simulation is being used. Dr. Keiji Tani from the Japan Atomic Energy Research Institute presented an overview of the recent developments in the Earth Simulator project and explained how this project, started in 1997, will be heading to its completion in 2002. The system recently was expanded with a new very high-performance one-chip vector processor to couple the three-fold objective of earth observation, basic research, and simulation modelling.
The Earth Simulator System is targeted at oceanographic and atmospheric knowledge, as well as at solid earth science. To respond to these aims, the system has to deliver a CPU and main memory of at least a 1000 times larger than the current supercomputers. The team therefore selected a distributed parallel system with vector processors with powerful interconnectivity capabilities through a single-stage crossbar network. The peak performance is 40 teraflops with an effective performance for an Atmospheric General Circular Model (AGCM) of more than 5 teraflops. The main memory has a size of 10 terabytes.
In order to make the Earth Simulator operational, the total number of 640 nodes is divided into 40 clusters. Each cluster thus has 16 nodes plus a Cluster Control Station (CCS), an input/output Control Station, and system disks. In fact, this turns the Earth Simulator into a batch-job system but Dr. Tani announced the introduction of a special TSS cluster in which one to two nodes will be applied for TSS jobs whereas the rest of the nodes are reserved for small scale batch jobs.
The basic system has been developed by NEC but a few specific Earth Simulator high level functions will have to be designed from scratch. These include large scalability for distributed memory parallel processing; total system control by the Super Cluster Control System (SCCS); large scale parallel input and output; and an interface for centre routine. The major function of the centre routine constitutes the optimal scheduling of submitted batch jobs as well as of files required for the job.
The new vector processor's performance has been evaluated in a series of tests. It was measured for every kernel loop and compared with one estimated in the basic design of the Earth Simulator by applying the software simulator GSSS which performs simulations of behaviours in principal parts of vector parallel processors. In each loop test, the vector processor, called OCVP-ES performs a tiny bit better than the one estimated by the GSSS and exceeds in efficiency all other processors in the same class.
Leslie Versweyveld |
 |