| Promising ''Pentium performance in a notebook,'' Mips
Technologies (Mountain View, CA) has announced the first
power-saving chip in its R4000 microprocessor family, an
important step toward moving RISC chips from workstations
to mainstream PCs. The R4200 is intended primarily for
laptops that can run Windows NT. Sample silicon wasn't available at press time, so all performance specifications are preliminary. According to Mips, the 3-V chip will use only 1.5 W at its top internal clock speed of 80 MHz (the external bus runs at 40 MHz). A reduced-power mode requires only 0.4 W, and a power-down mode turns off the chip altogether. Mips says the R4200 can be powered down and reactivated so quickly that a system could force the chip into power-down mode between keystrokes when you're typing. Mips estimates the R4200 will deliver 55 SPECmarks for integer operations (SPECint92) and 30 SPECmarks for floating-point operations (SPECfp92). By contrast, Intel's Pentium delivers 64.5 SPECint92 and 56 SPECfp92, respectively. The R4200 lacks the parallel pipelines found in the Pentium, but it does have separate hardware units for integer and floating-point instructions. Based on 0.6-micron process technology, the R4200 squeezes 1.3 million transistors onto a small die of 9.2 by 8.8 millimeters. It has a 16-KB instruction cache and an 8-KB data cache. The caches, MMU (memory management unit), and system interface can be removed from the chip, so the logic core can be used in embedded applications. Mips says the R4200 will be available in quantity late this year. Versions will be manufactured by Mips, NEC Electronics, and possibly other partners. No pricing was announced, but Mips says the goal is to sell the chip for $55, or $1 per SPECint. Copyright 1994-1997 BYTE |