below provides an overview of the most common terminologies related to
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(AC '97) defines a high-quality, 16-bit audio architecture for the PC that
is used in the majority of today's desktop platforms.
(Advanced Configuration and Power Interface) is
a power management specification that allows the operating system to control
the amount of power distributed to the computer's devices. Devices not in
use can be turned off, reducing unnecessary power expenditure. ACPI
defines a new interface to the system board, and enables the OnNow design
initiative for instantly available PCs.
Graphics Port) is a PCI-based interface that was designed
specifically for demands of 3D graphics applications. The 32-bit AGP
channel directly links the graphics controller to the main memory. While
the channel runs at only 66 MHz, it supports data transmission during both
the rising and falling ends of the clock cycle, yielding an effective speed
of 133 MHz. [top]
is an extension to the
AGP interface specification that meets the needs of advanced workstation
graphics. This specification is primarily designed to deliver additional
electrical power to the graphics add-in cards. The AGP Pro definition
includes an extended connector, thermal envelope, and mechanical
specifications for cards, I/O brackets, and motherboard layout requirements.
( AGP In-line Memory Module) - 4 MB Display
Cache card that plugs into the AGP port to gain additional performance.
(Audio Modem Riser) is Intel's specification on
motherboard design. Motherboard with this type of architecture allows for
designs w/o analog I/O functions. However, these functions can be added by
the codec chip on a riser card, which plugs into the motherboard
perpendicularly, resulting in better audio quality.
is two or more hard disk drives grouped together to appear as a single
device to the host computer. [top]
was the original form factor of IBM's PC.
( AT Attachment Packet Interface), also known as IDE or
ATA, is a drive implementation that includes the disk controller on the
device itself. It allows CD-ROMs and tape drives to be configured as master
or slave devices, just like hard drives. [top]
form factor was designed to replace the AT form factor. It improves on the
AT design by rotating the board ninety degrees, so that the IDE connectors
are closer to the drive bays, and the CPU is closer to the power supply and
cooling fan. The keyboard, mouse, serial, USB, and parallel ports are built
refers to carrying capacity. The greater the bandwidth, the more data the
bus, phone line, or other electrical path, can carry. Greater bandwidth,
then, also results in greater speed. [
(BIOS Boot Specification) is a feature within the BIOS
that creates, prioritizes, and maintains a list of all Initial Program Load
(IPL) devices, and then stores that list in NVRAM. IPL devices have the
ability to load and execute an OS, as well as provide the ability to return
to the BIOS if the OS load process fails for some reason. At that point,
the next IPL device is called upon to attempt loading of the OS.
Input/Output System) program resides in the ROM chip, and
provides the basic instructions for controlling your computer's hardware.
Both the operating system and application software use BIOS routines to
ensure compatibility. [top]
Bootable Array Support
refers to the ability to make the system boot from a RAID array instead of
from a standalone (single) disk.
Commonly integrated into server system boards that support IPMI, a Baseboard
Management Controller (BMC) normally features embedded functions, multiple
interfaces, and a generous number of general purpose I/O pins. Other common
features associated with a BMC would be a complete IPMI protocol stack with
IPMB support for intra-chassis communications, as well as ICMB for
buffer is a
portion of RAM that is used to temporarily store data, usually from an
application, though it is also used when printing, and in most keyboard
drivers. The CPU can manipulate data in a buffer before copying it, all at
once, to a disk drive. While this improves system performance -- reading to
or writing from a disk drive a single time is much faster than doing so
repeatedly -- there is the possibility of losing your data should the system
crash. Information stored in a buffer is temporarily stored, not
is a data pathway. The term is used especially to refer to the connection
between the processor and system memory, and between the processor and PCI
or ISA local buses. [top]
allows peripheral devices and IDEs to access the system memory without going
through the CPU (similar to DMA channels).
cache is a
temporary, fast storage area that holds data from a slower storage device
for quick access as needed by an application. Access time is fast using a
cache, because the needed information is stored in the SRAM instead of in
the slower DRAM. Note that the cache is also much smaller than your regular
memory: a typical cache size is 512KB, while you may have as much as 2GB of
regular memory. [
to the physical size of the cache onboard. This should not be confused with
the cacheable area, which is the total amount of memory that can be scanned
by the system in search of data to put into the cache. A typical setup
would be a cache size of 512KB, and a cacheable area of 512MB. In this
case, up to 512MB of the main memory onboard is capable of being cached.
However, only 512KB of this memory will be in the cache at any given
moment. Any main memory above 512MB could never be cached.
and open jumpers
Jumpers and jumper pins are active when they are On or Closed, and inactive
when they are Off or Open. [top]
(Complementary Metal-Oxide Semiconductors) are
chips that hold the basic start-up information for the BIOS.
(Communication & Network Riser)
(Color-decoder) is a filter that manipulates data in some
form, usually by compressing or decompressing the data stream. [top]
another name for the serial port, which is so-called because it transmits
the eight bits of a byte of data along one wire, and receives data on
another single wire (that is, the data is transmitted in serial form, one
bit after another). Parallel ports transmit the bits of a byte on eight
different wires at the same time (that is, in parallel form, eight bits at
the same time).
resides on an array that relieves the host CPU from executing
processor-intensive operations such as RAID 5 parity calculations and
secondary RAID 1 writes.
(Display C ache)
(Double Data Rate) is a technology designed to double
the clock speed of the memory. It activates output on both the rising and
falling edge of the system clock rather than on just the rising edge,
potentially doubling output.
(Dual In-line Memory Modules) are a faster and
more capacious form of RAM than SIMMs, and do not need to be installed in
sometimes called DIMM sockets, because the physical slot and the logical
unit are the same. That is, one DIMM module fits into one DIMM socket,
which is capable of acting as a memory bank.
D irect Memory Access channels are similar to IRQs.
DMA channels allow hardware devices (like sound cards or keyboards) to
access the main memory without involving the CPU. This frees up CPU
resources for other tasks. As with IRQs, it is vital that you do not double
up devices on a single line. Plug and Play devices will take care of this
for you. [top]
Doze mode ,
only the CPU's speed is slowed.
(Dynamic RAM) is a widely available, very affordable form of
RAM that has the unfortunate tendency to lose data if it is not recharged
regularly (every few milliseconds). This refresh requirement makes DRAM
slower by a factor of three to ten compares to non-recharged RAM such as
means mirroring across two RAID cards.
Dynamic Array Expansion
- see "Online
(Error-Correcting C ode) functions to test the accuracy
of data transmission, both in and out of memory. [top]
Data Output DRAM) a faster type of DRAM in that it can
start working on the next block of memory at the same time it sends previous
one to CPU.
(Electrically Erasable Programmable ROM) also
called Flash BIOS, is a ROM chip that can, unlike normal ROM, be updated.
This allows you to keep up with changes in the BIOS programs without having
to buy a new chip. TYAN's BIOS
A non-redundant power supply aimed at SSI-based server boards. The
specification defines a 450W or 550W power supply with 6 outputs; 3.3v, 5v,
12v1, 12v2, 12v3, -12v, and 5vSB. The form factor is stretch PS/2, with
connector/cable assemblies required for the motherboard power, remote
sensing and control functions, and peripheral power.
(Extended System Configuration Data) is a format
for storing information about Plug and Play devices in the system BIOS.
This information helps properly configure the system each time it boots.
refers to a system where one component can quickly be replaced without
causing a loss of service, such as in a RAID system. [top
is low level
software that controls the system hardware.
an industry term for the size, shape, power supply type, and external
connector type of the PCB (personal computer board) or motherboard. The
standard form factors are the AT and ATX, although TYAN also makes some
Baby-AT boards. [
The FirmWare Hub is a key component of the Intel Accelerated Hub
Architecture. Able to contain both the system BIOS and integrated
graphics/video BIOS on one component, the FirmWare Hub connects directly to
the I/O Controller Hub (ICH) without requiring an ISA bus.
is an onboard hardware timer, such as the Real Time Clock.
is a form of encryption. One system, typically the server, sends an
encryption scheme to another agent, typically a client. Thus, the client's
data is protected during transmittal to the server. [top]
(Hardware Compatibility Test) is a suite of tests from
WHQL that verifies hardware and device driver operations under a specific
Hard Disk Drive. [top]
Spare - A
spare hard drive will automatically be used to replace the failed member of
a redundant disk array.
to the ability to remove a failed member of a redundant disk array and
replace it with a good drive without bringing down the server or
interrupting transactions that involve other devices. [
controls the horizontal properties of the monitor.
(I ntegrated Circuit) is the formal name for the computer
The I/O Controller Hub is a highly integrated multifunctional controller
that provides the interface to the PCI bus, and integrates many of the
functions needed in today's PC platforms. It normally communicates with the
host controller (MCH) over a dedicated hub interface.
(Integrated Device/Drive Electronics) is a
simple, self-contained hard drive interface. It can handle drives up to
8.4GB in size. Almost all IDEs sold now are in fact Enhanced IDEs (EIDEs).
is a hardware interrupt signal that goes to the IDE. [top]
(Input / Output) is the connection between your computer and
another piece of hardware (mouse, keyboard, etc.).
(Initial Program Load): a feature built into
devices, describing those devices as capable of loading and executing an OS,
as well as being able to provide control back to the BIOS if the loading
The Intelligent Platform Management Interface (IPMI) is a hardware level
interface specification that defines a common, abstracted, message-based
interface to platform monitoring and control functions. As a hardware-level
interface, it sits at the bottom of a typical management software stack.
Thus, IPMI is "management software neutral." It can be exposed through any
standard management software interface, such as WMI, CIM, SNMP or DMI.
(Interrupt Request) is an electronic request that runs
from a hardware device to the CPU. The interrupt controller assigns
priorities to incoming requests and delivers them to the CPU. It is
important that there is only one device hooked up to each IRQ line; doubling
up devices on IRQ lines can lock up your system. Happily, Plug and Play
operating systems take care of these details for you. [top]
(Industry Standard A rchitecture) is a slower 8- or
16-bit BUS (data pathway).
(Local-Area Network) connects to workstations, PC's, or
other LANs to enable data access and device sharing. Wake-on-LAN refers to
ability to revive a system from sleep mode over a network without physically
touching the system. [
the amount of time that one part of a system spends waiting for another part
to catch up. This is most common when the system sends data out to a
peripheral device, and is waiting for the peripheral to send some data back
(peripherals tend to be slower than onboard system components).
The Memory Controller Hub (MCH) provides the system bus interface, memory
controller, AGP interface, and hub interface for I/O.
Commonly found in high-performance server and workstation designs where
maximum memory capacity is required, a Memory Expansion Card (MEC) is used
to allow for maximum memory slot availability (8, 12 or even 16 memory
sockets), without sacrificing motherboard real estate.
microATX form factor was developed as a natural evolution of the ATX form
factor to address new market trends and PC technologies. While offering the
same benefits of the ATX form factor specification, the microATX form factor
improves upon the previous specification in several key areas. Current
trends in the industry indicate that users require a lower-cost solution for
their PC needs. This form factor addresses the cost requirement by reducing
the size of the motherboard. The smaller motherboard is made possible by
reducing the number of I/O slots supported on the board. The overall effect
of these size changes reduces the costs associated with the entire system
- A processor on the RAID card which performs all RAID management functions
(for example, the Intel i960). Microprocessors offer higher performance
compared to co-processors.
(RAID 1) provides data protection by duplicating all data from a primary
drive on a secondary drive. [top]
(Network Operating System), i.e. NetWare, Windows NT
ROM and EEPROM are both examples of Non-Volatile RAM,
memory that holds its data without power. DRAM, in contrast, is volatile. [top]
(Original Equipment Manufacturers) refers to companies
such as Compaq or IBM that package other companies' motherboards and
hardware inside their case and sell them.
Capacity Expansion (O.C.E.)
- A process for adding storage capacity to an existing RAID array without
having to take the server offline. Also known as Dynamic Array Expansion.
, a term for a PC that is always on but appears off and that responds
immediately to user or other requests. [top]
transmits the bits of a byte on eight different wires at the same time (that
is, in parallel form, eight bits at the same time).
is a form of data protection used by RAID level 5 to recreate the data of a
failed drive in a disk array. [top]
is the 1999 - 2000 requirements for PC system and peripheral design for the
"Designed for Microsoft Windows" logo. Such as ACPI support and NO ISA
(P eripheral Component Interconnect) is a 32-bit local
bus (data pathway) which is faster than ISA bus. Local buses are those that
operate within a single system (as opposed to a network bus, which connects
multiple systems). [top]
Programmable Input / Output) modes are the data transfer
modes used by IDE drives. These modes use the CPU for data transfer (DMA
channels do not). PCI refers to the type of bus used by these modes to
communicate with the CPU.
allows you to connect multiple PCI devices onto one PCI slot. [top]
specification addresses the need for increased bandwidth of PCI devices.
PCI-X enables the design of systems and devices that operate at clock speeds
up to 133MHz, or 1GB per second. Furthermore, PCI-X protocol enhancements
enable devices to operate much more efficiently, thereby providing more
useable bandwidth at any clock frequency.
Pipeline burst SRAM
is a fast secondary cache. It is used as a secondary cache because SRAM is
slower than SDRAM, but usually larger. Data is cached first to the faster
primary cache, and then, when the primary cache is full, to the slower
improves system performance by allowing the CPU to begin executing a second
instruction before the first is completed. A pipeline can be likened to an
assembly line, with a given part of the pipeline repeatedly executing a set
part of an operation on a series of instructions.
Management timers) are software timers that count down the
number of seconds or minutes until the system times out and enters sleep,
suspend, or doze mode. [top]
is an acronym for Plug and Play, a design standard that has become ascendant
in the industry. Plug and Play devices require little set-up to use.
Novice end users can simply plug them into a computer that is running on a
Plug and Play-aware operating system (such as Windows 95), and go to work.
Devices and operating systems that are not Plug and Play require you to
reconfigure your system each time you add or change any part of your
(Preboot Execution Environment) is one of the four
components that makes up the Wired for Management 2.0 baseline
specification. PXE was designed to define a standard set of preboot
protocol services within a client, towards the goal of allowing networked -
based booting to boot using industry standard protocols.
Array of Independent Disks) is a way of storing same
data in different places on many hard drives. By using this method, the
data is stored redundantly, also the multiple hard drives will appear as a
single drive to the operating system. RAID level 0 is known as striping,
where data is striped (or overlapped) across multiple hard drives, but
offers no fault-tolerance. RAID level 1 is known as mirroring, which stores
the data within at least two hard drives, but does not stripe. RAID level 1
also allows for faster access time and fault-tolerance, since either hard
drive can be read at the same time. RAID level 0+1 is both striping and
mirroring, providing fault-tolerance, striping, and faster access all at the
same time. [
more on RAID
through 5) refer to different array architectures that offer various
advantages in terms of data availability, cost and performance. RAID levels
0, 1, 0/1, and 5 are the most popular. [
- See "
Combines RAID 0 (data striping) and RAID 1 (disk mirroring).
- See "
data striping (for enhanced performance) with distributed parity (for data
protection) to provide a recovery path in case of failure.
makes installation, configuration, and management of RAID arrays easy.
Often includes features such as pager notification and remote management.
(Random Access Memory), while technically referring to
a type of memory where any byte can be accessed without touching the
adjacent data, is often used to refer to the system's main memory. This
memory is available to any program running on the computer. [top]
Developed by Rambus, Inc., RDRAM, or Rambus DRAM, is currently the fastest
memory technology used by PCs. While today's most common SDRAM delivers data
at a maximum speed of 133MHz, RDRAM currently transfers data at up to
800MHz. RDRAM is expected to be seen in 1066MHz and 1200MHz iterations in
the coming months and years.
(Read-Only Memory) is a storage chip which contains the
BIOS (Basic Input / Output System), the basic instructions required to boot
the computer and start up the operating system.
(Small Computer System Interface) is the
technology that allows you to connect various devices to your PC. This
connection is made using a SCSI card that fits inside your computer. [top]
(S ynchronous Dynamic RAM) is so-called because it can
keep two sets of memory addresses open simultaneously. By transferring data
alternately from one set of addresses, and then the other, SDRAM cuts down
on the delays associated with non-synchronous RAM, which must close one
address bank before opening the next.
is so called because it transmits the eight bits of a byte of data along one
wire, and receives data on another single wire (that is, the data is
transmitted in serial form, one bit after another). [top]
(Single In-line Memory M odules) are the most
common form of RAM. They must be installed in pairs, and do not have the
carrying capacity or the speed of DIMMs.
SIMM sockets are the physical slots into which you stick SIMM modules. A
pair of SIMM sockets forms a SIMM bank, and act as a unit. If only one
socket is filled, the bank will not operate. [top]
Sleep / Suspend mode,
all devices except the CPU shut down.
(Shared Memory A rchitecture) with system memory.
two-wire interface through which simple system and power management related
chips can communicate with the rest of the system. It is based on the
principals of the operationof I2C.
(System Management Bus) is a two-wire interface based
on the I2C protocol. It is a low-speed bus that provides positive
addressing for devices, as well as bus arbitration.
(Symmetric MultiProcessing) is a computer architecture
that provides fast performance by making multiple processors available to
complete individual processes simultaneously. Unlike asymmetrical
processing, any idle processor can be assigned any task, and additional
processors can be added to improve performance and handle increased loads. A
variety of today's operating systems and hardware configurations are
available to support SMP. Specific applications can benefit from SMP if the
code provides for multithreading. SMP uses a single operating system and
shares common memory and disk input/output resources. Windows NT, Windows
2000, Windows XP Professional and many flavors of Linux and UNIX support SMP.
Static RAM, unlike DRAM, does not need to be refreshed in
order to prevent data loss. Thus, it is faster, and more expensive.
Intel is currently working with leading server OEMs and industry suppliers
to help gain ground for the SSI form factor initiative. The goal of the SSI
initiative is to deliver a set of specifications covering two primary server
elements: power supplies and electronic bays, and thus lay the groundwork
for future growth in the server market. The initiative is similar to such
desktop PC efforts as ATX and NLX, in that it is working to define common
packaging elements for the server market.
the video and fixed disk drive shut down; all other devices operate
Striping (RAID 0)
- Spreads data evenly
over multiple drives to enhance performance. Because there is no redundancy
scheme, it does not provide data protection.
is a fast version of the old DMA channel. UltraDMA is also called UltraATX.
Without UltraDMA controller, your system cannot take advantage of the higher
data transmission rates of the new UltraDMA/UltraATA HDDs.
(Universal Serial Bus) is a versatile port. It can
function as a serial, parallel, mouse, keyboard, or joystick port. It is
fast enough to support video transfer, and is capable of supporting up to
127 daisy-chained peripheral devices. [top]
Channel Memory) is the new SDRAM architecture, which realizes
flexible and high-efficiency data transfer by incorporating channel buffers
configured by high-speed registers.
Array) is the PC video display standard. [top
Regulator Module) regulates the voltage fed to the
controls the vertical properties of the monitor. [top]
( Wired for Management) is an Intel guideline on the
implementation of system management.
(Windows Hardware Quality Libs) is the test
procedure for "Designed for Microsoft Windows" logo. [top]
Insertion Force sockets) make it possible to insert
CPUs without damaging the sensitive pins. The CPU is lightly placed in an
open ZIF socket, and the metal lever pulled down. This shifts the processor
over and down, guiding it into place on the board.