It was one of the first machines to use a vector processor to improve performance on appropriate scientific applications.

The design was part of a bid made to Lawrence Livermore National Laboratory (LLNL) in the mid-1960s.

[5] Livermore was looking for a partner who would build a much faster machine on their own budget and then lease the resulting design to the lab.

A number of basic design features of the machine meant that its real-world performance was much lower than expected when first used commercially in 1974, and was one of the primary reasons CDC was pushed from its former dominance in the supercomputer market when the Cray-1 was announced in 1975.

The STAR also fetched vector operands in 512-bit units (superwords), reducing average memory latency.

The stream unit accesses the main memory through the SAC via three 128-bit data buses, two for reads, and one for writes.

The first has a floating point adder and multiplier, and the second can execute all scalar instructions.

This forced most programs to pay the high setup cost of the vector units, and generally the ones that did "work" were extreme examples.

Any time that the program had to run scalar instructions, the overall performance of the machine dropped dramatically.

Two STAR-100 systems were eventually delivered to the Lawrence Livermore National Laboratory and one to NASA Langley Research Center.

The failure of the STAR led to CDC being pushed from its former dominance in the supercomputer market, something they tried to address with the formation of ETA Systems in September 1983.