Hardware User's Guide

Intel® RAID Controller RS25FB044 Hardware User’s Guide 1
1 Overview
The Intel
®
RAID Controller RS25FB044 reliable and fault-tolerant disk subsystem
management based on the Intel
®
Entry Hardware RAID (IR) Stack. This is an ideal RAID
solution for the internal or external large capacity storage needs of mid to low-end servers
and workstations for use by workgroups and departmental-sized organizations or
individuals. The Intel
®
RAID Controller RS25FB044 offers a cost-effective way to
implement RAID in a server for internal or external storage.
The Intel
®
RAID Controller RS25FB044 addresses the growing demand for increased
data throughput and scalability requirements across mid to low-end servers and
workstations. This adapter supports third generation PCI Express* at launch.
The controller can be connected to up to eight drives directly and allows the use of
expanders to connect to additional drives. For more information about the use of
expanders, see the ANSI SAS Standard, version 2.0 specification.
SATA and SAS are serial, point-to-point, device interfaces that use simplified cabling,
smaller connectors, lower pin counts, and lower power requirements than parallel SCSI.
Benefits of SAS and SATA
SAS is a serial, point-to-point, enterprise-level device interface that leverages the proven
SCSI protocol set. SAS is a convergence of the advantages of SATA, SCSI, and FC, and is
the future mainstay of the enterprise and high-end workstation storage markets. SAS
offers a higher bandwidth per pin than parallel SCSI and improves signal and
data integrity.
The SAS interface uses the proven SCSI command set to ensure reliable data transfers,
while providing the connectivity and flexibility of point-to-point serial data transfers. The
serial transmission of SCSI commands eliminates clock skew challenges. The SAS
interface provides improved performance, simplified cabling, smaller connectors, lower
pin count, and lower power requirements than parallel SCSI.
SAS controllers leverage a common electrical and physical connection interface that is
compatible with Serial ATA technology. The SAS and SATA protocols use a thin, 7-wire
connector instead of the 68-wire SCSI cable or 40-wire ATA cable. The SAS/SATA
connector and cable are easier to manipulate, connect to smaller devices, and do not
inhibit airflow. The point-to-point SATA architecture eliminates difficulties created by the
legacy ATA master-slave architecture, while maintaining compatibility with existing
ATA firmware.