HARDSOF

NORTHBRIDGE

Also known as the memory controller hub (MCH) in Intel systems (AMD, VIA, SiS and others usually use ‘northbridge’), is traditionally one of the two chips in the core logic chipset on a PC motherboard, the other being the southbridge. Separating the chipset into the northbridge and southbridge is common, although there are rare instances where these two chips have been combined onto one die when design complexity and fabrication processes permit it.

The northbridge on a particular system’s motherboard is the most prominent factor in dictating the number, speed, and type of CPU(s) and the amount, speed, and type of RAM that can be used. Other factors such as voltage regulation and available number of connectors also play a role. Virtually all consumer-level chipsets support only one processor series, with the maximum amount of RAM varying by processor type and motherboard design. Pentium-era machines often had a limitation of 128 MB, while most Pentium 4 machines have a limit of 4 GB. Since the Pentium Pro, the Intel architecture can accommodate physical addresses larger than 32 bits, typically 36 bits, which gives up to 64 GB of addressing (see PAE), though motherboards that can support that much RAM are rare because of other factors (operating system limitations and expense of RAM).

A northbridge typically will only work with one or two different southbridges. In this respect, it affects some of the other features that a given system can have by limiting which technologies are available on its southbridge partner.

The northbridge hosts its own memory lookup table (I/O memory management unit), a mapping of the addresses and layout in main memory. The northbridge handles data transactions for the front side bus [[FSB), the memory bus and the AGP port.

The northbridge will have a different model number, even though they are often paired with the same southbridge to come under the collective name of the chipset.

The Intel Hub Architecture (IHA) has replaced the northbridge/southbridge chipset. The IHA chipset also has two parts: the Graphics and AGP Memory Controller Hub (GMCH) and the I/O Controller Hub (ICH). The IHA architecture is used in Intel's 800 series chipsets, which is the first x86 chipset architecture to move away from the northbridge/southbridge design.

SOUTHBRIDGE

Also known as the I/O Controller Hub (ICH) in Intel systems (AMD, VIA, SiS and others usually use 'southbridge'), is a chip that implements the "slower" capabilities of the motherboard in a northbridge/southbridge chipset computer architecture. The southbridge can usually be distinguished from the northbridge by not being directly connected to the CPU. Rather, the northbridge ties the southbridge to the CPU

FUNCTIONS:

• PCI bus. The PCI bus support includes the traditional PCI specification, but may also include support for PCI-X and PCI Express.
• ISA bus or LPC Bridge. Though the ISA support is rarely utilized, it has interestingly managed to remain an integrated part of the modern southbridge. The LPC Bridge provides a data and control path to the Super I/O (the normal attachment for the keyboard, mouse, parallel port, serial port, IR port, and floppy controller) and FWH (firmware hub which provides access to BIOS flash storage).
• SPI bus. The SPI bus is a simple serial bus mostly used for firmware (e.g., BIOS) flash storage access.
• SMBus. The SMBus is used to communicate with other devices on the motherboard (e.g. system temperature sensors, fan controllers).
• DMA controller. The DMA controller allows ISA or LPC devices direct access to main memory without needing help from the CPU.
• Interrupt controller. The interrupt controller provides a mechanism for attached devices to get attention from the CPU.
• IDE (SATA or PATA) controller. The IDE interface allows direct attachment of system hard drives.
• Real Time Clock. The real time clock provides a persistent time account.
• Power management (APM and ACPI). The APM or ACPI functions provide methods and signaling to allow the computer to sleep or shut down to save power.
• Nonvolatile BIOS memory. The system CMOS, assisted by battery supplemental power, creates a limited non-volatile storage area for system configuration data.
• AC97 or Intel High Definition Audio sound interface
• Baseboard Management Controller

HARD DISK DRIVE

A hard disk drive (HDD), commonly referred to as a hard drive, hard disk, or fixed disk drive,^[1] is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, “drive” refers to a device distinct from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk. Early HDDs had removable media; however, an HDD today is typically a sealed unit (except for a filtered vent hole to equalize air pressure) with fixed media.^[2]

HDDs (introduced in 1956 as data storage for an IBM accounting computer^[3]) were originally developed for use with general purpose computers. In the 21st century, applications for HDDs have expanded to include digital video recorders, digital audio players, personal digital assistants, digital cameras and video game consoles. In 2005 the first mobile phones to include HDDs were introduced by Samsung and Nokia.^[4] The need for large-scale, reliable storage, independent of a particular device, led to the introduction of embedded systems such as RAID arrays, network attached storage (NAS) systems and storage area network (SAN) systems that provide efficient and reliable access to large volumes of data.

HARD DISK

JUMPER SETTINGS

Jumper settings determine the order in which EIDE hard drives

and other devices attached to a single interface cable are

detected by a computer system. On SATA hard drives, jumper

settings enable or disable enterprise-level features.

Setting the jumpers correctly on a hard drive requires the

proper placement of a plastic-encased, metal jumper shunt over

two pins on the hard drive jumper block, as shown in Figure 1.

SATA Hard Drive Jumper Settings

WD SATA hard drives are factory set for workstation/desktop

use. For enterprise storage requirements, the jumpers can be set to

enable spread spectrum clocking or power-up in standby modes.

WD SATA drives are shipped from the factory either with or

without a jumper shunt in the spread spectrum clocking (SSC)

enable/disable position (on pins 1 and 2). It is not necessary

to add or remove the jumper shunt on the drive for

workstation/desktop use. For enterprise storage enviroments, use

the following advanced settings:

SSC Mode (Default 1): spread spectrum clocking feature enabled

or disabled. Default 1 setting is disabled or jumper shunt placed

on pins 1–2. Removing the jumper enables the spread spectrum

clocking feature.

SSC Mode (Default 2): spread spectrum clocking feature enabled

or disabled. Default 2 setting is disabled or no jumper shunt

placed on pins 1–2. Adding the jumper to pins 1–2 enables the

spread spectrum clocking feature.

EIDE Hard Drive Jumper Settings

WD EIDE hard drives are factory set with Cable Select (CSEL)

jumper settings. The CSEL jumper setting protocol requires

the use of a special interface cable. All hard drives in a

CSEL-compliant system have the jumpers set in the same position.

Not all computer systems support Cable Select. The

Master/Slave jumper setting protocol must be used if a system does

not support CSEL or if CSEL support cannot be determined. The

Master/Slave protocol works regardless of whether or not the

system, devices, or cable selects CSEL.

Some systems with legacy BIOSs lock up on initial boot or

report a smaller drive capacity than the actual capacity of the hard

drive. In such cases, alternate jumper settings must be used in

conjunction with WD’s Data Lifeguard Tools software.

Three common jumper setting configuration protocols are

used for EIDE drives:

! Single: the hard drive is the only device on the IDE interface

cable.

! Master/Slave: the hard drive is either a Master (C:/) drive or a

Slave drive in a multiple-drive system.

! Cable Select (CSEL/CS): jumper settings are the same on all

hard drives in a system (both single- and multiple-drive

systems); however, a special CSEL cable must be used, and the

host system must support CSEL. WD EIDE hard drives are

factory set for Cable Select configuration.

Note: Not all computer systems and motherboards support the

CSEL option.

Cable Select System Support

Consult the system documentation or contact the system

manufacturer to determine whether a computer supports CSEL.

Checking the jumper position on an existing hard drive or

other EIDE device (such as a CD-ROM drive) is another method

to determine whether a system supports CSEL. If a diagram or

explanation of jumper settings on top of the hard drive or IDE

device verifies that it is jumpered for Cable Select, then the system

supports CSEL protocol.

The Master/Slave configuration protocol must be used when a

system does not support CSEL or when CSEL support cannot be

determined.

Note: Even when the system, devices, and cable support CSEL,

using jumpers on the hard drive(s) for Master/Slave protocol still

works.

Single Hard Drive Installations

To install your new WD hard drive as the only hard drive in

your system, use jumpers as shown in Figure 3.

Cable Select Installations: Connect the hard drive to the black

connector at the end of the IDE interface cable.

Figure 3. EIDE Single Hard Drive Jumper Settings

Dual Hard Drive Installations

To install your new WD EIDE hard drive with an existing hard

drive or CD-ROM on the same interface cable, be sure all drives

are jumpered as shown in Figure 4.

Note: Not all hard drive manufacturers use the same jumper

configurations. To install a new WD hard drive on the same

interface cable with a non-WD hard drive, obtain jumper setting

information from the manufacturer of the non-WD hard drive.

Figure 4. EIDE Dual Hard Drive Jumper Settings

Cable Select Installations: connect the intended boot drive (the first

hard drive to be detected) to the black or end connector of the IDE

interface cable. Connect the storage drive (the second hard drive to

be detected) to the gray or middle connector of the IDE interface

cable.

Master/Slave Installations: to install your new WD hard drive with

an existing drive on separate IDE interface cables, leave the

jumper(s) in default positions for possible future use. The system

recognizes each drive as a single, stand-alone drive. Master/slave

jumper settings are used only when there are two devices on the

same IDE interface cable.

Reduced Power Spinup (RPS)™ Mode

Implementation of RPS requires a jumper on the 4-pin jumper

block of a WD 2.5-inch EIDE drive. To configure the drive for

RPS mode, place a jumper shunt on pins B–C as shown in

Figure 5. A 2.54 mm mini jumper shunt (low profile) is required.

Multiple hard disks

To install your new WD EIDE hard drive with an existing hard

drive or CD-ROM on the same interface cable, be sure all drives

are jumpered as shown in Figure 4.

Note: Not all hard drive manufacturers use the same jumper

configurations. To install a new WD hard drive on the same

interface cable with a non-WD hard drive, obtain jumper setting

information from the manufacturer of the non-WD hard drive.