Author: Tonya Comer, Product Marketing Manager, Industry Standard Servers, HP
Serial Attached SCSI (SAS) holds the promise of the future for SMB users who will eventually need more input/output per second (IOPS) performance, easier connectivity and greater scalability, as storage requirements continue to escalate. As SAS products begin to enter the market in 2005, SMB customers will appreciate the time and effort that has gone into the definition, development, and standardization of this innovative refinement to long-standing SCSI technology.
More affordable for SMB customers than Fibre Channel and more robust and reliable than Serial ATA (SATA), SAS will be able to fulfill the SMB customer requirements and provide the necessary performance and scalability to move data at gigabit speeds—speeds that meet or exceed current storage I/O performance found in Parallel ATA (PATA), SATA, SCSI or Fibre Channel systems.
SMB customers will also benefit from the freedom to choose either SAS or SATA hard disk drives or both, depending on storage applications, because they are both operable on the same SAS backplane. Finally, SAS is the logical evolution that preserves the SCSI advantages while leveraging the SATA electrical and physical connection.
The industry has already transitioned from PATA to SATA technology. The latter is the foundation of a new storage interface replacement architecture that is as cost-effective as PATA and has greater performance improvement potential.
A natural question arises regarding SAS/SATA compatibility: when should an SMB customer specify SAS hard disk drives, and when should they use SATA hard disk drives? The answer is based on their inherent differences. SAS hard disk drives are used when supporting few to many users simultaneously in a 24×7 computing environment, while SATA hard disk drives are designed for a lower level of use and lower cost.
SMB customers who require performance, reliability, and software consistency with current SCSI deployments should select SAS hard disk drives because SAS:
- Meets the requirements for enterprise storage by providing strict quality, reliability standards, and universal compatibility
- Is the best choice for transactional data and 24×7 operation server and storage market segments
- Has the best price for performance with full duplex and 3.0 Gb/s bandwidth
- Has nearly unlimited connectivity, with the ability to host up to more than 16,000 devices
- Is a multi-initiator and has dual-port disk drives that provide redundant connections for high availability
One the other hand, SMB customers who require an inexpensive server and storage deployment should consider SATA because it:
- Is the best choice for reference data and eight to 10 hours of operation for server and storage environments that are not heavily utilized and can sustain lower reliability than typical enterprise environments
- Is the lowest cost per gigabyte
- Has performance with half duplex and 1.5 Gb/s bandwidth
Serial technologies encompass a set of innovations that change the familiar parallel interconnect between a server and its storage device. SAS embraces the best features of other serial storage solutions and provides SMB customers a roadmap for innovation and improvement for many years to come.