GRAPE-4: a teraFLOPS massively parallel special-purpose computer system for astrophysical N-body simulations

We are developing a massively parallel special-purpose computer system for astrophysical N-body simulations, GRAPE-4 (Gravity-Pipe 4). The GRAPE-4 system is designed to simulate dynamics of classical particles which interact each other gravitationally by using predictor-corrector methods. We have developed two application-specific LSIs, the HARP (Hermite Accelerator Pipe) chip and the PROMETHEUS chip for the GRAPE-4 system. The HARP chip calculates gravitational forces and its performance exceeds 600 megaFLOPS. The PROMETHEUS chip calculates predictors for the time-integration. Using multi-chip module technology, we can integrate 1920 HARP chips into a single system. The GRAPE-4 system consists of 4 clusters, which are connected to a single host workstation. The peak speed of GRAPE-4 will exceed 1 teraFLOPS even in the worst case, and will reach around 1.8 tetraFLOPS in the typical case