A spectral atmospheric general circulation model called AFES (AGCM for Earth Simulator) was developed and optimized for the architecture of the Earth Simulator (ES). The ES is a massively parallel vector supercomputer that consists of 640 processor nodes interconnected by a single stage crossbar network with its total peak performance of 40.96 Tflops was achieved for a high resolution simulation (T1279L96) with AFES by utilizing the full 640-node configuration of the ES. The resulting computing efficiency is 64.9% of the peak performance, well surpassing that of conventional weather/climate applications having just 25-50% efficiency even on vector parallel computers. This remarkable performance proves the effectiveness of the ES as a viable means for practical applications.

This paper describes a High-speed Prolog Machine (HIM) architecture and its hardware structure, which are developed as a product of Fifth Generation Computer System (FGCS} project in Japan.HIM realizes high performance and provides a practical programming environment.A major HIM feature is a large memory capacity and specialized hardware for unification and stack operations.HIM has a compiler-oriented architecture with high-level stack-control instructions.Furthermore, the HIM architecture provides side-effect operations, nonlocal-exit control and multiprocess support primitives, which are effective to develop system programs.The performance is estimated at 280 KLIPS (Kilo Logical Inferences Per Second) in executing a deterministic "concatenate" Prolog program.The HIM processor is implemented with high-speed CCML {Current Mode Logic) chips and with I00 nanosecond machine cycle.