澳门金沙平台开户网址在哪里:Technology: Computer firms take the RISC route to greater power

 作者:骆杠     |      日期:2019-03-03 07:12:11
By PRATAP CHATTERJEE Desktop computers are set to become more powerful if a group that includes 21 of the world’s biggest computer companies has its way. The companies recently signed an agreement in New York to develop a standard for computers that use a technique known as reduced instruction set computing (RISC). This technique, which is already employed in workstations, could then be extended to personal computers as well. This would allow personal computers and workstations to communicate and work together, and should make high-speed computing more widely available. The new standard is known as the Advanced Computer Environment. Under the ACE agreement, companies will model their RISC chips on a single, agreed architecture based on a microprocessor due to be launched next year by the Californian semiconductor manufacturer MIPS. Ace is backed by some of the biggest computer manufacturers in the world, including Compaq, Digital Equipment Corporation, Olivetti and Siemens Nixdorf, as well as the software giant Microsoft. But some big companies who already sell RISC computers have not signed the agreement, including Hewlett-Packard, IBM and Sun Microsystems. Sun presently sells a RISC chip that commands two-thirds of the market and is most threatened by the new MIPS chip. Scott McNealy, Sun’s chief executive, says that ACE falls into ‘that old Texas category of big hat, no cattle’. Computer instructions are partly built into the microprocessor chip, where calculations are carried out, and partly in the external software. Computer scientists soon discovered, however, that conventional processor chips spent 80 per cent of their time executing 20 per cent of their repertoire of instructions. RISC computing moves the less frequently used instructions to the software. The software is then more complex, but the RISC chips are simpler and run their calculations much faster. In addition to using RISC techniques, the MIPS chip, known as the R4000, has longer and more complex data words (64 bits long) than the 32-bit words of most other chips. The combination of the RISC computing, 64-bit words and improved software means that the chip can perform 50 million instructions per second (mips). The most powerful personal computers only reach speeds of 5 mips while workstations can reach 16 mips. ACE will develop the software needed to control the RISC processors. The first will be a version of Unix, one of the most popular systems in use today for large computers that have a number of users. The second is a version of the software currently being developed by Microsoft for controlling personal computers,