S845WD1-E Server Board - Viglen Download

Functional Architecture
S845WD1-E Server Board TPS
3.8.2 ATA-100
The S845WD1-E server board provides an embedded dual channel ATA-100 bus through the
use of the Promise Technology PDC20267 ASIC. The PDC20267 ATA-100 controller contains
two independent ATA-100 channels that share a single 32-bit, 33-MHz PCI bus master interface
as a multifunction device, packaged in a 128-pin PQFP.
The ATA-100 controller supports the following features:
• The scatter / gather mechanism supports both Direct Memory Access (DMA) and
Programmable I/O (PIO) IDE drives.
• Support for ATA PIO Mode 0, 1, 2, 3, 4, DMA Mode 0, 1, 2, and Ultra DMA Mode 0, 1, 2, 3,
4, 5.
• The IDE drive transfer rate is capable of up to 100 MB/sec per channel.
• The host interface complies with PCI Local Bus Specification Revision 2.2.
• 32-bit, 33-MHz bus speed and 132 MB/sec sustained transfer rate.
The Promise* PDC20267 supports IDE RAID through dual ATA-100 Channels. In a RAID
configuration, multiple IDE 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 IDE RAID can be configured as followings:
• RAID 0: Striping one to four drives.
• RAID 1: Mirroring two drives.
• RAID 1 +: Spare drive (three drives).
• RAID 0 +: One to four drives are required.
RAID 0 configurations are used for high-performance applications, as it doubles the sustained
transfer rate of its drives. RAID 1 configurations 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 dual ATA-100 channels, two striped drive pairs can mirror each other (RAID 0+1) for
storage capacity and data redundancy.
3.8.3 Video Controller
The S845WD1-E server board provides an ATI Rage XL PCI graphics accelerator, along with 8
MB of video SDRAM and support circuitry for an embedded SVGA video subsystem. The ATI
Rage XL chip contains a SVGA video controller, clock generator, 2D and 3D engine, and
RAMDAC in a 272-pin PBGA.
The SVGA subsystem supports a variety of modes, up to 1600 x 1200 resolution in 8/16/24/32
bpp modes under 2D, and up to 1024 x 768 resolution in 8/16/24/32 bpp modes under 3D. It also
supports both CRT and LCD monitors up to 100 Hz vertical refresh rate.
The S845WD1-E server board provides a standard 15-pin VGA connector and supports
disabling of the on-board video through the BIOS Setup menu or when a plug-in video card is
installed in the AGP slot or any of the PCI slots.
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Intel order number A93850-002
Revision 2.0