Machine type: Vectorprocessor.
Models: S-820/15, S-820/20, S-820/40, S-820/60, S-820/80.
Operating system: VSP/S (IBM MVS compatible) or UXP/M (a Unix
variant acquired from Amdahl).
Compilers: Vectorising Fortran 77/VP both under VSP and UXP, C.
System parameters:
Performance:
Note: 
and 
are only given for the largest configuration.
The S-820 has been only marketed in Japan and was as such the predecessor of the current Hitachi S-3000 series. As in most Japanese vector processors, the clock cycle of the scalar processor is two times higher as that of the VPU.
The memory bandwidth is 1 load/store and 1 load pipe per arithmetic pipe set which is fairly good as Japanese vector processors go, but is lower than that in Cray machines (2 loads, 1 store per arithmetic pipe set).