STA

Author: Sam Sawyer, Director of Product Marketing
Embedded Storage Products
Emulex Corporation

Introduction
One of the hottest topics in storage is the adoption of solid state disks (SSDs) within external storage arrays. Over the last decade, advances in hard disk drive (HDD) capacity have far outpaced the random IOPS capability of HDDs, providing a catalyst for the increased adoption of SSDs. Inherent in the mechanical nature of HDDs is a latency that creates a significant bottleneck in the movement of data to and from the storage array. Common methods of improving the IOPS capability in storage systems include high-rotational speed HDDs and striping the data across additional disk drives, yet these approaches do not dramatically improve IOPS performance. Instead, they result in a dramatic increase in power consumption. SSD technology, by contrast, can vastly improve IOPS performance (by a factor of up to 1,000) while reducing total power consumption of a storage array.

Author: Tonya Comer, Product Marketing Manager
HP

Serial Attached SCSI (SAS) incorporates differential signaling, which reduces the effects of capacitance, inductance, and noise experienced by parallel SCSI at higher speeds. SAS links are full duplex (Figure 1); they send and receive information simultaneously, thereby reducing a major source of latency inherent in parallel SCSI. Unlike traditional parallel SCSI that shares the bandwidth of one bus with many devices, SAS is a point-to-point technology that provides maximum bandwidth to each device, greatly improving scalability and performance. All end devices (initiators and targets) have a connection point called a port. Expanders and HBAs have multiple ports. A port can contain one or more transceiver mechanisms, or phys. A narrow port has only one phy, while a wide port has more than one phy.

Author: Anil Vasudeva, President and Chief Analyst
IMEX Research

Industry Trends

Explosion in the growth of Storage Data
The internet has been the catalyst behind the explosive growth of digital information, growing at an annual rate of 60% and estimated to reach 1,800 Exabytes by 2011. Regardless of the state of the economy, the amount of data that needs to be stored, accessed and managed will continue to grow exponentially, especially as new types of data such as that from social networking and internet video continues to mushroom.