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 VAXinstruction set architecture (ISA). Equipped with optional vector processors, they were marketed into the supercomputer space as well. 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, at that time the high-end VAX offering. The initial plans called for two general models, the high-performance 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.

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 had left the mainframe market in 1983 due to the success of the VAX line, but since then IBM compatiblepersonal computer systems and the new 32-bit Unixworkstation machines had taken over the low end and were pushing into the midrange. They felt the only response was to move back into the high-end mainframe space, and do do so they would need to offer a machine that was as powerful as IBM's best, run VAX software, and be significantly less expensive as well.

Engineers within the company continually expressed their concern that the complex design would soon be outperformed by RISC systems and the general improvement in the CMOS field. Internal fighting broke out between the teams working on the 9000 and single-chip solutions like DEC's own NVAX, which offered a significant fraction of the 9000's performance for a tiny fraction of the price. The project was nearly cancelled on multiple occasions, but always managed to be re-instated. The company spent an estimated $1 billion on development, and sold only a handful of systems before cancelling it and replacing it with CMOS-based machines.

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.