ARCHITECTURE AND THE SOFTWARE ENVIRONMENT OF PARALLEL COMPUTER CENJU-4

This paper describes the architecture and operating system, and gives an evaluation of NEC's new parallel computer Cenju-4 Major features of Cenju-4 are: a) parallel memory architecture which encompasses distri buted shared memory and user-level inter-processor communication. b) S calable system from 8 nodes to 1,024 nodes. Using the powerful RISC pr ocessor VR10000 (200 MHz) from MIPS II Technologies, Inc., Cenju-4 sys tem can be configured from 8 nodes to 1,024 nodes, flexibly extending the system as the demand arises. c) Utilization of a flexible micro-ke rnel operating system. Since the system adopts a micro-kernel based op erating system (MACH), it can be configured into several software envi ronments such as UNIX double dagger server systems and, single system image systems. The key components of the system are two 1 M gate array s which implement memory control, inter processor communication contro l and network communication controls. The programming environment prov ided are de-facto standard libraries, high-level programming languages such as MPI (Message Passing Interface), PVM (Parallel Virtual Machin e) and HPF (High Performance Fortran). The operating system and the in ter-processor communication libraries fully exploit the functionality of the hardware to realize an inter-processor communication latency of 4.5 mu s and the throughput of 169 MB/s at user program level.