The Nintendo 64 Video Game Console

Delivering Workstation-Level 3D Graphics at Consumer Prices

The speed, stunningly realistic 3D graphics and high-fidelity audio of the new Nintendo 64 video game console have received a lot of attention as the world's leading video-game maker gets ready to launch the industry's first true 64-bit game console. Combining a workstation-grade, 64-bit MIPS RISC processor with a sound and graphics coprocessor incorporating Silicon Graphics Reality Immersion Technology, Nintendo's goal from the outset was to deliver the world's best video game experience at a retail price under $250, less than the cost of the competition's older, less capable, 32-bit consoles.

Nintendo has been able to achieve this price/performance breakthrough through a highly efficient design that combines a high level of functional integration with a high-bandwidth unified memory architecture. The final design includes only four chips of any consequence -- the 64-bit MIPS RS4300i CPU; the Reality Coprocessor integrating all graphics, audio and memory management functions; and two memory chips. Key to Nintendo's success in meeting its target price point while also meeting its performance demands was its decision to base its design on high-bandwidth, low-cost Rambus memory technology.

Industry sales of older-generation 8- and 16-bit video game consoles have fallen significantly, but analysts at Dataquest, Inc., a market research company, expect the overall market slide to slow in 1996 and then reverse itself in 1997 as shipments of next-generation 32- and 64-bit consoles start to drive new market growth. Dataquest predicts 32- and 64-bit video game console shipments will climb from less than 5 million units in 1995 to nearly 18 million by the turn of the century.

In the knock-down, drag-out, shoot-em-up world of consumer video games, the winners are the companies that can provide game players with the most compelling video game experience at the lowest possible cost. In today's market, that means nothing less than hair-trigger responsiveness, truly realistic, three-dimensional graphics and CD-quality, stereo sound. Noticing the failure of current 32-bit systems to deliver these qualities, Nintendo set out to skip an entire generation of technology and develop a 64-bit system capable of delivering a quantum leap in graphics realism.

The simplicity of a unified memory architecture appealed to Nintendo's engineers for its cost-cutting potential, but in order to meet their performance goals they estimated it would require a bandwidth of at least 450 megabytes per second to handle all the CPU, graphics and audio functions. Traditional approaches -- using a 64-bit data path to EDO or synchronous DRAM -- could not meet both the performance and cost goals. The Rambus solution exceeded Nintendo's bandwidth requirements while costing less than synchronous DRAM, and resulted in additional system cost savings through lower pin count, simplified design, less board real estate and lower power requirements.

Compared to its competitors, Nintendo's design approach is the epitome of simplicity. The 32-bit Sega Saturn utilizes seven individual processors for CPU, CD-ROM management, audio, video and bus management functions linked by an elaborate bus system to separate main, video, audio and CD-ROM buffer memories made up of synchronous DRAM, video RAM and fast-page-mode DRAM. Likewise, the 32-bit Sony Playstation incorporates multiple custom processors for CPU, graphics, audio and other functions and multiple memory systems using various RAM technologies. This partitioning into separate functional sections requires many more chips and achieves lower overall performance at higher cost.

The Rambus technology provides Nintendo with a bandwidth of 562.5 megabytes per second using a 31-pin interface to the memory controller. A system using 64-bit-wide synchronous DRAM, by comparison, requires a 110-pin interface to the memory controller. In the Nintendo 64, the Rambus interface not only simplified the board layout, but also increased the total system integration by making it possible to fit the memory controller on the same die as the graphics and sound functions and have it all still fit in a single, low-cost, 160-pin package.

The Rambus interface also enables Nintendo to offer the only game console on the market with consumer-installable system memory expansion. The compact, low-cost Rambus upgrade socket measures just 1.5 inches long and uses only 36 pins. Expanding a 64-Bit SDRAM system, by comparison, requires a socket over 5 inches long with 168 pins.

The Rambus memory subsystem -- just two chips -- occupies only 1.5 square inches of board space, compared to the 6 square inches required for an equivalent SDRAM design. This space saving combined with the additional integration made possible by the low-pin-count Rambus interface enabled Nintendo to fit all its components on a board measuring just five by six inches, one quarter the size of the system board used in the Sega Saturn. In addition, Nintendo was able to implement the Rambus-based design using a two-layer board instead of the four layers used in the Sega Saturn.

The cost savings Nintendo realized by choosing the Rambus solution over the 64-bit SDRAM solution are considerable. The ability to use a two-layer implementation alone saved Nintendo $5 per unit in manufacturing costs. Taken altogether, Nintendo estimates the total bill of materials cost savings over an equivalent SDRAM-based design was about 20 percent.

Now, PC vendors are taking a hard look at the leading video game machines as they prepare systems to match these new speed, graphics and sound benchmarks. Already, Chromatic Research and Cirrus Logic have announced PC multimedia and graphics products employing Rambus technology to help PC vendors achieve these goals. Nintendo has boldly taken what until now had been considered exotic processor and memory technologies and launched them squarely into the mainstream consumer electronics market. At the same time, they have demonstrated beyond a doubt the ability of Rambus technology to meet the performance requirements of a high-bandwidth unified memory architecture while providing a substantial cost savings.

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