Western Digital Ultra ATA 100 Extends Existing Technology While Increasing Performance and Data Integrity free download

File name Ultra ATA 100 Extends Existing Technology While Increasing Performance and Data Integrity.pdf

Ultra ATA/100 Extends Existing Technology While Increasing Performance and Data Integrity High-Speed Hard Drive Interface Increases the Ultra ATA/66 Burst Transfer Rate to 100 MB/s Overview/Executive Summary PC performance increases steadily from year to year due to the constant development of high-speed microprocessors. As microprocessors become faster and faster, a corresponding increase in data transfer rates between hard drives and system memory is required. For desktop and portable computers, the Advanced Technology Attachment (ATA) interface is the most popular protocol for moving data between the hard drive controller and system memory. Ultra ATA/100 is the latest version of the ATA hard drive data transfer protocol. A low- cost extension of the Ultra ATA/66 hard drive interface, Ultra ATA/100 increases burst data rates significantly over previous iterations of the protocol. Also known as Ultra DMA/100 and Feature ATA, Ultra ATA/100 allows host computers to send and receive data at 100 MB/s--considerably faster than the 66.6 MB/s data transfer speeds of Ultra ATA/66. The result is maximum disk performance under PCI local bus environments. At its fast burst data rates, Ultra ATA/100 will go farther than Ultra ATA/66 in removing bottlenecks associated with data transfers, especially during sequential operations. Ultra ATA/100 also delivers heightened data integrity to the EIDE interface through use of a 40-pin 80-conductor cable, and CRC (Cyclic Redundancy Check) error detection code. The 80-conductor cable reduces crosstalk and improves signal integrity by providing 40 additional ground lines between the 40-pin IDE signal and ground lines. The connector is plug-compatible with existing 40-pin headers, and the incremental cost for the cable should be minimal. As with Ultra ATA/66, CRC ensures the integrity of transferred data. 40-Conductor Cable 80-Conductor Cable 40-pin IDE Interface Figure 1. Ultra ATA/100 40-Pin, 80-Conductor Cable Newly introduced Western Digital hard drives support Ultra ATA/100. They transmit and receive data at higher rates, and thereby provide better performance. The Ultra ATA/100 protocol is also endorsed by the industry's leading chipset and motherboard manufacturers. Ultra ATA/100 hard drives are 100 percent backwards compatible with Ultra ATA/66, Ultra ATA/33, and DMA, as well as with existing EIDE/IDE hard drives, CD-ROM drives, and host systems. Background Ultra ATA/100 is the latest ATA/IDE hard drive data transfer protocol for moving data between the hard drive buffer and the system memory. The previous interface was Ultra ATA/66, with a maximum burst transfer rate of 66.6 MB/s. Prior to Ultra ATA/66 was Ultra ATA/33 with a maximum burst transfer rate of 33.3 MB/s. By increasing the burst transfer rates of IDE drives, Ultra ATA/100 brings the effective trans- fer rate of the system's bus and the drive's