CYRIX Corp has launched its 486DX2-V66 Central Processing Unit for the notebook segment and introduced its 486DX2-V80 CPUs for desktop systems. These products enhance Cyrix's full line of 486DX/DX2 microprocessors. Combining three volt operation with power management features and performance enhancements they are ideal for today's portables and green PCs. ''We're pleased to announce these products as the first fruit of our new relationship with IBM,'' said Steve Domenik, vice-president of marketing at Cyrix. ''Their state-of-the-art processing capabilities, coupled with Cyrix's designs, are yielding outstanding product.'' Cyrix has held a strong position in the 486 notebook market for more than a year. By providing a three volt 486DX2-V66 CPU that outperforms and provides lower power than the DX4-75, Cyrix intends to keep that position. This new CPU is manufactured with advanced 0.6 micron CMOS technology that has true three volt transistors and is, therefore, able to achieve high clock speeds. Combined with additional performance and power management features, this microprocessor offers a performance increase of up to 10 per cent over the DX4-75. The 486DX2-V80 outperforms the standard 486DX2-66 CPUs by 10 to 20 per cent as a result of Cyrix's integrated write-back cache. ''Because cache miss penalties increase considerably at high clock speeds, write-back cache technology becomes essential in systems at 66MHz or above,'' said Kevin McDonough, vice-president of engineering at Cyrix. The Cx486DX2-V80 will be priced at $US294, offering better value than the Intel 486DX2-66. Cyrix's unique microcode and innovative designs have allowed them to improve on the industry's previous 486DX2 feature set. Increasing performance and reducing power in PCs is achieved through the integrated eight kilobyte write-back cache, System Management Mode (SMM), and an enhanced floating point unit. Cyrix's write-back cache technology increases application performance over the older write-through cache technology. These performance benefits are most significant in memory-write-constrained systems, such as clock-doubled systems, higher clock speed systems, and portables. Because write-back cache completes memory writes inside the cache - without accessing main memory - unnecessary external memory writes are reduced by up to 98 per cent.