VAX 9000

The VAX 9000 is a discontinued family of mainframes developed and manufactured by Digital Equipment Corporation (DEC) using custom ECL-based processors implementing the VAX instruction set architecture (ISA). Equipped with optional vector processors, they were marketed into the supercomputer space as well.^[1] As with other VAX systems, they were sold with either the VMS or Ultrix operating systems.

The systems trace their history to DEC's 1984 licensing of several technologies from Trilogy Systems, who had introduced a new way to densely pack ECL chips into complex modules. Development of the 9000 design began in 1986, intended as a replacement for the VAX 8800 family,^[2] at that time the high-end VAX offering. The initial plans called for two general models, the high-performance Aquarius using water cooling as seen on IBM systems, and the midrange-performance Aridus systems using air cooling. During development, engineers so improved the air cooling system that Aquarius was not offered; the Aridus models were "field-upgradeable" to Aquarius, but they did not offer it.^[3]

The 9000 was positioned within DEC as an "IBM killer", a machine with unmatched performance at a much lower price point than IBM systems. DEC intended the 9000 to allow the company to move back into the mainframe market, which it had abandoned starting in 1983,^[4] as it watched the low end of the computer market being taken over by ever-improving IBM compatible personal computer systems and the new 32-bit Unix workstation machines. The company invested an estimated $1 billion in the development of the 9000, in spite of considerable in-company concern about the concept in the era of rapidly improving RISC performance. Production problems pushed back its release, by which time these fears had come true and newer microprocessors like DEC's own NVAX offered a significant fraction of the 9000's performance for a tiny fraction of the price.

Roughly four dozen systems were delivered before production was discontinued,^{[citation needed]} a massive failure. One representative example CPU sits in storage at the Computer History Museum, not on public display. Another is in storage at the Large Scale Systems Museum.