【NEC】 ACOS System 3800

In July 1990, NEC announced a general-purpose computer, the ACOS System 3800, which was the fastest in the world at the time. Using a single processor, this machine achieved performance about 2.7 times better than the ACOS System 1500 Series by using innovations such as 20,000-gate logic VLSI with a delay time per gate of 70 picoseconds, bipolar RAM with an access time of 1.6 nanoseconds, 1-megabit SRAM, 4-megabit DRAM and other LSI, high-density packging technology for mounting 100 VLSI on a large ceramic substrate of 22.5 centimeters square, and sophisticated bipolar technology incorporating an independently developed branch prediction mechanism and bypass mechanism.

The system achieved superior expandability by realizing a multiprocessor configuration with up to a maximum of 6 processors, and an "expansion data space" specifically for data with a maximum capacity of 128 terabytes.

In order to improve the reliability of multiplex configurations where multiple systems are linked, the system enabled back-up from other multiple systems using the reciproca standby system, and smooth job resumption at high-speed via a job resumption function mediated by the expansion memory unit in case of back-up. In this way, a high-reliability system was achieved.