Benefits Of The Sas Interface; Figure 1. Example Of An Intel Sas Direct-Connect Application; Figure 2. Example Of An Intel Sas Raid Controller Configured With An Lsisasx12 Expander - Intel 12Gb/s User Manual

The following figure shows a direct-connect configuration. The Inter-IC (I
communicates with peripherals. The external memory bus provides a 32-bit memory bus,
parity checking, and chip select signals for pipelined synchronous burst static random
access memory (PSBRAM), nonvolatile static random access memory (NVSRAM), and
Flash ROM.
The following figure shows an example of a SAS RAID controller configured with an
LSISASx12 expander that is connected to SAS drives, SATA III drives, or both.
Figure 2. Example of an Intel SAS RAID Controller Configured with an

Benefits of the SAS Interface

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 Fibre
Channel, and it is the future mainstay of the enterprise and high-end workstation storage
markets. SAS offers a higher bandwidth per pin than parallel SCSI, and it improves signal
and data integrity.
4

Figure 1. Example of an Intel SAS Direct-Connect Application

SAS/SATA III Device
SAS/SATA III Device
SAS/SATA III Device
SAS/SATA III Device
LSISASx12
Expander
SAS
PCI Express
RAID Controller
PCI Express Interface
LSISASx12 Expander
PCI Express Interface
8
SAS RAID Controller
LSISAS3108
PCI Express to SAS ROC
2
C) interface
32-Bit Memory
Address/Data
Flash ROM/
Bus
PSBRAM/
NVSRAM
2
I C
Interface
2
I C
Peripheral
Bus
Flash ROM/
NVSRAM/
2
I C/UART
72-bit DDR3
with ECC
Interface
SRAM
SDRAM SRAM SRAM
LSISASx12
Expander
12Gb/s Intel® RAID Controllers User Guide