S875WP1-E TPS
Functional Architecture
Revision 4.0
19
3.3.3
SATA RAID with Promise Technology
*
PDC20319
The Intel Server Board S875WP1LX provides additional four port Serial ATA through the use of
the Promise* Technology PDC20319 ASIC. The PDC20319 SATA-150 controller contains four
independent SATA channels that share a single 32-bit, 33-MHz PCI bus master interface as a
multifunction device, packaged in a 144-pin LQFP.
The PDC 20319 controller supports the following features:
•
Burst bus mastering and advanced packet command based scatter/gather engine to
enhance overall system performance
•
Built in 4 channels SATA PHY, which meets the SATA 1.0 specification and can transfer
data with 1.5GHz speed
•
Capable to support multiple arrays and quad master mode for dedicated SATA channel,
up to four physical drive can operated at master mode.
•
Quad independent data paths with read ahead and write posting supported for quad IDE
channels to have high performance
•
PCI interface that complies with PCI Local Bus Specification Revision 2.3 and PCI power
management 1.1
•
Support 48-bit LBA format for drives larger than 128GB
•
32-bit, 33-MHz bus speed and 150 MB/sec sustained transfer rate.
The Promise* PDC20319 supports SATA RAID through four SATA Channels. The RAID
Engine supports advance chained packet commands for XOR and four independent ATA
operations improving performance for all RAID levels. In a RAID configuration, multiple SATA
hard drives are placed into one or more arrays of disks. Each array is seen as an independent
disk, though the array may include upwards of two, three, or four drives. The SATA RAID can
be configured as follows:
•
RAID 0:
Striping one to four drives.
•
RAID 1:
Mirroring two drives.
•
RAID 10:
Striping and mirroring of data concurrently (requires 4 drives)
RAID 0 configurations are used for high-performance applications, as it doubles the sustained
transfer rate of its drives. RAID 1 configurations are primarily used for data protection. It creates
an identical drive backup to a secondary drive. Whenever a disk write is performed, the
controller sends data simultaneously to a second drive located on a different data channel. With
four drives attached to four SATA channels, one pair of striped drives can mirror themselves to
another pair (RAID 10) for storage capacity and data redundancy.