RM5231

The R5000 is a microprocessor that implements the MIPS IV instruction set architecture (ISA) developed by Quantum Effect Design (QED). The project was funded by MIPS Technologies, Inc (MTI), also the licensor. MTI then licensed the design to Integrated Device Technology (IDT), NEC, NKK, and Toshiba. The R5000 succeeded the QED R4600 and R4700 as their flagship high-end embedded microprocessor. IDT marketed its version of the R5000 as the 79RV5000, NEC as VR5000, NKK as the NR5000, and Toshiba as the TX5000. The R5000 was sold to PMC-Sierra when the company acquired QED. Derivatives of the R5000 are still in production today for embedded systems.

Users of the R5000 in workstation and server computers were Silicon Graphics, Inc. (SGI) and Siemens-Nixdorf. SGI used the R5000 in their O2 and Indy low-end workstations. The R5000 was also used in embedded systems such as network routers and high-end printers. The R5000 found its way into the arcade gaming industry, R5000 powered mainboards where used by Atari and Midway. Initially the Cobalt Qube and Cobalt RaQ used a derivative model, the RM5230 and RM5231. The Qube 2700 used the RM5230 microprocessor, whereas the Qube 2 used the RM5231. The original RaQ systems were equipped with RM5230 or RM5231 CPUs but later models used AMD K6-2 chips and then eventually Intel Pentium III CPUs for the final models.

The original roadmap called for 200 MHz operation in early 1996, 250 MHz in late 1996, succeeded in 1997 by R5000A. The R5000 was introduced in January 1996 and failed to achieve 200 MHz, topping out at 180 MHz. When positioned as a low-end workstation microprocessor, the competition included the IBM and Motorola PowerPC 604, the HP PA-7300LC and the Intel Pentium Pro.

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