Machine type: Shared-memory multi-vectorprocessor.
Models: Y-MP M90.
Operating system: UNICOS (Cray Unix variant).
Compilers: Fortran, C, C++, Pascal, ADA.
The M90 is especially produced for applications that need a large memory. Because DRAM chips are used instead of the faster (and bulkier) SRAM chips for the memory, the clock cycle is rather that of the former Cray Y-MP, 6 ns, than that of the currently sold C90 systems with a clock cycle of 4 ns. As also the number of numerical vector pipes are the same as that from the former Y-MP, the performance is 333 Mflop/s per processor.
The availability of a large real memory is important for Cray users as Cray does not support virtual memory. Therefore, the market for these systems in the realm of applications with very large memory requirements but where the speed of the system is not absolutely crucial.