Chip Hall of Fame: Sun Microsystems SPARC Processor

Using an unproven new architecture, this processor put Sun Microsystems on the map


There was a time, long ago (the early 1980s), when people wore neon-colored leg warmers and watched “Dallas,” and microprocessor architects sought to increase the complexity of CPU instructions as a way of getting more accomplished in each compute cycle. But then a group at the University of California, Berkeley, always a bastion of counterculture, called for the opposite: Simplify the instruction set, they said, and you’ll process instructions at a rate so fast you’ll more than compensate for doing less each cycle. The Berkeley group, led by David Patterson, called their approach RISC, for reduced-instruction-set computing.

As an academic study, RISC sounded great. But was it marketable? Sun Microsystems (now part of Oracle) bet on it. In 1984, a small team of Sun engineers set out to develop a 32-bit RISC processor called SPARC (for Scalable Processor Architecture). The idea was to use the chips in Sun’s new line of workstations. One day, Scott McNealy, then Sun’s CEO, showed up at the SPARC development lab. “He said that SPARC would take Sun from a $500-million-a-year company to a billion-dollar-a-year company,” recalls Patterson, a consultant to the SPARC project.

If that weren’t pressure enough, many outside Sun had expressed doubt the company could pull it off. Worse still, Sun’s marketing team had had a terrifying realization: SPARC spelled backward was…CRAPS! Team members had to swear they would not utter that word to anyone, even inside Sun—lest the word get out to archrival MIPS Technologies, which was also exploring the RISC concept.

The first version of the minimalist SPARC consisted of a “20,000-gate-array processor without even integer multiply/divide instructions,” says Robert Garner, the lead SPARC architect and now an IBM researcher. Yet, at 10 million instructions per second, it ran about three times as fast as the complex-instruction-set computer (CISC) processors of the day.

Sun would use SPARC to power profitable workstations and servers for years to come. The first SPARC-based product, introduced in 1987, was the Sun-4 line of workstations, which quickly dominated the market and helped propel the company’s revenues past the billion-dollar mark—just as McNealy had prophesied.