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comparison with the SH4

SEGA's CPU Choices Hitachi's SH-4 The SH-4's Floating Point Unit How Many Bits?/Software Modem There are a number of considerations that Sega had to make when deciding on a CPU for the Dreamcast. The most important considerations are power to cost ratio, manufacturing volumes, and heat dissipation. Why Sega went with the Hitachi SH-4: very high performance at a low cost 360 MIPS, 1.4 GFlops for around $30 Hitachi has the manufacturing ability to provide millions of SH-4s the SH-4 does not need a fan for heat dissipation reducing cost simplifying system design smaller, less expensive, lower weight power supply needed Sega's software engineers are familiar with programming SH series chips Sega has good relations with Hitachi Sega had some input in the design of the SH-4 floating point unit designed to excel at calculating matrix math arrays able to run Windows CE 2.1 Here is a comparison of the Hitachi SH-4 and the NEC Vr4300. The Vr4300 is used by Nintendo in the Nintendo 64 game console. The current Sony Playstation game console uses a LSI Logic custom MIPS architecture CPU based on the Silicon Graphics R3000 chip. So we can also expect Sony to go with a more advanced version of a MIPS chip with the Playstation 2. It has been rumored that Toshiba has the contract to provide the CPU for the Playstation 2. Toshiba is a SGI semiconductor manufacturing partner, so I suspect that Toshiba will provide Sony with a custom version of the MIPS R5000 chip.
Silicon Graphics MIPS Group
SH series
MIPS series
Clock Rate
200 MHz
133 MHz
MIPS Rating
360 MIPS
173 MIPS
Floating Point Rating
1400 MFlops¹ (900 MFlops sustained with external memory)
133 MFlops
Pipeline 5 stages 5 stages Superscaler yes no Instruction Cache 8 KByte 16 KByte Data Cache 16 KByte 8 KByte Data Bus 64-bit 32-bit address/data multiplex Bus Frequency 100 MHz 66 MHz Power Dissipation 1.5 Watts Typical (@200MHz) 2.4 Watts Typical (@133MHz) IC Process 0.25 µm, four-layer metal 0.35 µm, three-layer metal Transistors 3.2 million ?? Die Size 42.25mm² 45mm² Package 208 or 256 pin package 120-pin Availability January, 1998 Now Estimated Mfg Cost² ? US$11 Price(10K)² US$30 US$32