White Paper - Serial Ata 0906

WHITE PAPER THE ARRIVAL OF SERIAL ATA

WHY SETTLE? TRENDS INTRODUCING SERIAL ATA THE SERIAL ATA FEATURE SET: MORE BANG FOR YOUR BUCK WHY USE PROMISE SERIAL ATA WHY SETTLE? The Internet has propelled a whole new generation of data-intensive applications requiring storage architectures that can scale on the fly and remain available all the time. With audio/video streaming, web commerce, and data warehousing applications, to name a few, storage will have to be a scalable network resource that can deliver capacity and data on the fly. However, in today’s world of shrinking IT budgets, many companies are forced to settle for what they can afford. Traditionally, high performance technology was only available to high-level enterprise companies who were willing and able to dig deep into their corporate pockets. But if you’re pockets don’t run as deep, should you really have to settle? Because “It’s ALL About Your Data”, Promise Technology doesn’t believe in settling. Promise Technology, Inc., the originator and global leader in ATA RAID storage solutions is committed to its goal of creating and promoting breakthrough affordable technology that will ensure that you never have to settle again. Promise is dedicated to providing high performance, reliable solutions at attractive price points. That’s why we are pioneering the way for support of cost-effective, high performance Serial ATA architectures by providing highly reliable, mature solutions as Serial ATA products come to market this year.

TRENDS ATA, (Advanced Technology Attachment), has main storage bus early days of computers. Continued improvements in and the relatively of ATA devices in dominance in market. The ATA standard is a interface, that multiple bits are transmitted at

been the since the personal speed low cost resulted the PC current parallel meaning of data one time.

Advances in high speed networking coupled with the limitations of the current parallel bus architecture have created a bottleneck in today’s networks. This has resulted in a shift away from

traditional interfaces in favor of serial connections to the disk drive with the associated scalability, reliability, and performance benefits

INTRODUCING SERIAL ATA A side-by-side comparison of a Parallel ATA hard drive (left) Designed to meet the needs of networked and a Serial ATA hard drive (right). storage, SATA (Serial ATA) was created to address the increased data rate demand while at the same time resolving many issues that prevented today’s ATA interface from being widely used in the enterprise. SATA grew out of the need to support growing bandwidth requirements that current Parallel ATA would be unable to maintain in future years. Serial ATA can be referred to as SCSI 4– 320MB/sec an evolutionary Serial ATA 2– 300MB/sec replacement for SCSI 3– 160MB/sec Serial A ta is 50% faster the Parallel ATA than Parallel A TA Serial ATA 1– 150MB/sec physical storage Parallel ATA/100– 100MB/sec interface. The Parallel ATA/66– 66MB/sec new Serial ATA architecture introduces a data communication standard for fast-talking drives, which will effectively increase bandwidth by 50%, assuring maximum performance. Serial ATA’s point-to-point architecture directly connects each device to the host via a dedicated link. Each device, therefore, has the entire bandwidth dedicated to it, so there is no interaction between devices. Serial ATA eliminates parallel ATA’s master/slave relationship, in which the master device controls the other slave device on the bus, allowing direct communications with any device on the bus. Serial ATA 3– 600MB/sec

Serial ATA architectures only change the physical interface layer. It conforms to the ATAPI (AT Attachment Packet Interface) command set, which is the standard used in today’s ATA drives. It also maintains register and software backward compatibility with Parallel ATA. No device driver changes are necessary and the Serial ATA architecture is transparent to the BIOS and the operating system. This means that Serial ATA is software compatible to parallel ATA drives ensuring a smooth transition from software and driver perspectives, allowing existing applications to work seamlessly with Serial ATA drives. The current Serial ATA specification maps out a 10 year growth plan with three generations of speed enhancements with generation one running at 150 MB/s (to stay ahead of disk data transfer rate and to remove the bottleneck that may occur with 100 MB/s parallel ATA), followed by 300 MB/s and 600 MB/s respectively.

SERIAL ATA FEATURE SET Cabling — Current Parallel ATA cables are bulky, as well as being limited to 18 inches in length. The wide, flat parallel ATA ribbon cables can be difficult to route, and their shape and bulk can restrict air flow inside a chassis or storage enclosure. Serial ATA cables are much smaller and can be up to 1-meter (about 39 inches). The smaller serial cable is easier to route inside the chassis, making them well-suited for storage boxes and high-density server

requirements. The smaller diameter cable can also help improve airflow inside the chassis and will facilitate future designs of smaller PC systems. Serial Transmission — Using 8B/10B Serial transmission to transfer data over the serial cable eliminates crosstalk and other problems that may occur with parallel data transmission. 8B/10B serial transmission is used in numerous technologies including Gigabit Ethernet and Fibre Channel. This encoding data integrity checking is required during high speed data transfer. Data Robustness — Serial ATA will offer more through checking and error correcting capabilities than are currently available with Parallel ATA. The end-to-end integrity of transferred commands and data can be guaranteed across the serial bus. Low ASIC Pin Count — Enables ASIC’s to be smaller, which improves cost-effectiveness on both devices and hosts. Software Compatibility — Serial ATA is compatible at the register level with Parallel ATA. This means Serial ATA requires no existing software and operating systems in order to function, and it provides backward compatibility with existing operating environments. To system software, a Serial ATA device is the same as a legacy ATA device. From a software point of view, this compatibility with legacy hardware ensures an easy transition and faster acceptance. Hot Plug — Though Promise has long supported hot plug on the Parallel ATA side with its patented Sideband Technology, hot plug has not been part of the ATA specification. Serial ATA allows devices to be hot-plugged and inserted directly into receptacles. The Serial ATA protocol provides the mechanical and electrical features necessary to allow devices to be directly inserted and removed while the system is powered.

THE SERIAL ATA FEATURE SET: MORE BANG FOR YOUR BUCK As you can see, Serial ATA addresses networking issues such as signal integrity, reduced pin count, low voltage, and improved cable and connector plants for smaller form factor drives. Such a feature set will prove to make the Serial ATA technology a viable alternative to SCSI in desktop and server/networked storage markets—all at a fraction of the cost.

WHY USE PROMISE SERIAL ATA Promise’s vision for Serial ATA is that its low cost, high reliability and scalable connectivity will create a vast market for inexpensive networked storage solutions enabling new applications for RAID protected data. As it has in the past, Promise is leading the way so that the advantages of Serial ATA RAID will be fully realized across the whole corporate data set. The Serial ATA specification and architecture align with Promise’s mission of maximizing user return on investment by providing high performance, reliable, and available technology that won’t put a dent in your pocket books. Promise’s line of Serial ATA products demonstrate a strong commitment to the next generation of powerful, yet inexpensive storage devices for the next generation of PCs and servers, creating low cost storage solutions without compromising performance or reliability, thus leveling the playing fields so that all users have the freedom to compete. With 14 years of ATA experience, over 10 million ATA ASIC’s shipped in just the last 3 years, and the most mature and reliable ATA RAID Engine in the industry, Promise has long since established itself as the leader of ATA RAID technology. We work closely with

virtually every major hard drive manufacturer, tier 1 OEM, and motherboard maker in their ongoing design and test programs, assuring product compatibility and feasibility. We are committed to promoting products that provide investment protection by reducing the cost and complexity of deploying mission critical storage services. Also, by developing and completely owning our own technology (ASIC, RAID engine, Drivers, and BIOS) Promise has a clear and unobstructed view of the progress being made towards long-term technology development and insight into near-term technology transitions such as Serial ATA. How did Promise consistently maintain its leadership position in ATA and ATA RAID? Simple—by not only meeting our customers’ expectations but exceeding them. We plan to do the same for Serial ATA. By continuing to push forward the limits of ATA storage performance and reliability, as well as driving the move to Serial ATA architectures that offer performance boosts and greater design freedoms, Promise will continue to provide fast, reliable and economical storage solutions well into the future.

The Promise SATA150 TX4 Controller enables up to four Serial ATA hard drives in your current PC.

Promise —It’s ALL About Your Data.