Serial ATA... the future?
What is Serial ATA?
Serial ATA is a \"serial\" architecture as opposed to today\'s \"parallel\" ATA internal disc drive bus. Serial ATA wraps many bits of data into a packet and then at a higher speed (up to 50% higher) than parallel, transfers the packet of data down the wire to or from the host. Today Cyclic Redundancy Checking (CRC) is performed on the data being transmitted back and forth but not on the commands. Serial ATA integrates CRC on the command and data packet level for enhanced bus reliability. Cyclic redundancy code detects all single and double-bit errors and ensures detection of 99.998% of all possible errors. A Serial ATA drive can transfer data at 150MB/sec on the bus to the host system with extremely reliable accuracy and the Serial ATA interface will continue to allow scalability for a very long time.
| Generation 1 | Generation 2 | Generation 3 | |
|---|---|---|---|
| Approximate Data Rate | 150mb/sec | 300mb/sec | 600mb/sec |
| Approximate Bus Speed | 1.5gb/sec | 4gb/sec | 6gb/sec |
| Approximate Introduction | Winter of \'02 | Mid \'04 | Mid \'07 |
Additional Benefits
In addition to a faster, more reliable bus, Serial ATA improves cabling and connectors for a robust yet simpler integration. Gone are the days of bent pins and clumsy cabling and needless returned hard drives. Serial ATA cables are thinner and longer for improved system airflow and innovative system designs such as small form factor and consumer electronic boxes. Connectors are easier to snap into place without any pins but rather a blind-mate type of connection. Without the wide cables, system integrators can easily route the longer data cables (1 meter) within the system for simplicity or innovative designs.
Seagate Technology, A Native in Serial ATA Still in its early market entry stage, Serial ATA provides immediate benefits to desktop users. Serial ATA, an innovative new interface, allows continued performance growth, enhanced data reliability, and overall improved system dynamics above and beyond what Parallel can efficiently continue to provide.
A true \"Native\" Serial ATA solution offers customers the \"Real McCoy\" in Serial ATA technology. By implementing Serial ATA technology, not only on the physical layer of the drive, but also in the ATA controller link and transport layers, Seagate drives can communicate from the drive to the host directly up to the full 150MB/sec speed on the bus. In addition, the native solution incorporates command queuing, which can be a big performance boost in operating systems that can take advantage of that type of function. Some drive manufacturers may not immediately offer these \"native\" Serial ATA features on their 1st generation Serial ATA drives due to the difficulty of this integration.
