Hitachi Data Systems has announced an integrated vector facility for its AS/EX Series mainframes models 50 to 100. The new vector comes just a few weeks before the mainframe marketing company reports its annual results, when it is expected to break the $1,000m mark, a 30% to 40% increase on last year’s figures. The vector consists of three packages and implements 171 instructions with 16 vector registers, each one consisting of 256 32-bit elements. AS/EX Models 50 and 60 can have a single vector facility, Models 65 to 80 support two vectors, Model 90 supports three, and Models 95 and 100 go up to four. Hitachi Data says that performance is application-dependent, but it believes that the results of the Livermore Fortran Kernels benchmark shows that performance increases as the start-up overhead is spread across a greater number of elements. A Livermore benchmark of an EX60 and the new vector running under MVS/XA 2.2 with VS Fortran 2.4 came up with the following results. Vector lengths range between scalar, short, medium, and long. The arithmetic average in Mflops was 15.88, 13.34, 20.13, and 22.82 respectively. The harmonic mean, also in MFLOPS, was 10.91, 8.15, 11.87, and 12.54. Hitachi Data says that the Engineering Scientific Subroutine Library is used extensively in the optimisation of vector code, and it claims that the combination can provide a six times performance increase on base scalar results. The new vectors will be supported under MVS/XA, ESA, VM/XA, and VM/SP HPO. It will be in limited availability under MVS in the second quarter of 1990, and generally available in the third quarter. Hitachi Data has no date as yet for vector support under VM.
