Chpt3 the System Board

8/9/2019 Chpt3 the System Board

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Chapter 3Chapter 3

The System Board


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Slide 2Ver 1.0 18 April 2001

Chapter ObjectivesChapter Objectives

What are Components on the System Board? How data moves

How to set CPU and system bus frequency for the system board


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MotherboardMotherboard

What is the Purpose of theMotherboard?Main circuit board in the computerwhere everything comes together. Thisis where you plug in your processor,memory, cache, video card and othercards. It is also where you connect yourperipherals.

What are the other names thatMotherboard is know as?Planar board, System board, Mainboard

Field Replaceable Unit (FRU)

CPU

ROM BIOS chip

CMOS battery

RAM

Which components can be found in theMotherboard?

CPU (Central Processing Unit)

Chip Set/Controller

System Clock

BUS

ROM BIOS

CMOS configuration chip and itsbattery

RAM

RAM cache (older system board)

System bus with expansion slots

Jumper and DIP switches

Ports

Power supply unit

Dip Switch


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Motherboard Contributing FactorsMotherboard Contributing Factors

How does it affects the Computer?Organization: Everything is connected to the motherboard. The design of themotherboard determines how the entire computer is going to be organized.

Control: The Chipset and BIOS program, which between them control most ofthe data flow within the computer.

Communication: All communication between the PC and its peripherals, otherPCs, and you, the user, goes through the motherboard.

Processor Support: Dictates your choice of processor for use in the system

Peripheral Support: Determines what types of peripherals you can use in yourPC. For example, the type of video card use (ISA, VLB, PCI) depends onwhat system buses it has

Performance: Determine system's performance for 2 reasons. First, themotherboard determines what types of processors, memory, system buses,

and hard disk interface speed your system can have, and these componentsdictate system's performance. Second, the quality of the motherboardcircuitry and chipset themselves have an impact on performance.

Upgradability: Its capabilities determine to what extent you will be able toupgrade your machine


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Form FactorForm Factor

What is the term Form Factor means?Describes the motherboard:

general shape

what sorts of cases

power supplies it can use

physical organization

For example, a company can make twomotherboards that have basically thesame functionality but that use adifferent form factor, and the only realdifferences will be the physical layoutof the board, the position of thecomponents

What are the common Factor Factorused?

AT and ATX.

What is the advantage of ATX overAT?

1. More efficient design

2. Disk drive cable connectors nearerto the drive bays

3. CPU closer to the power supply andcooling fan

4. Integrating more I/O onto theboard

5. Less cables and components in thesystem

6. Optimized power supply.

7. Side-mounted fan, directly cooling

the processor and add-in cards


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AT/ATX characteristicsAT/ATX characteristics

What is main characteristics of AT?1. Older design

2. Voltage supplies are 5 and 12 volts

3. Uses 2 power connectors, P8 andP9

What is the main characteristics ofATX?

1. Newer design

2. Voltage supplies are 5, 12 and 3.3volts Better power-managementfeature eg software enable power-on switch.

3. Use 1 power connector called P1


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IntelIntel--CPU Motherboard Diagram (AT)CPU Motherboard Diagram (AT)

CPU is at the

end of expansion

slots and tend to

obstruct the

expansion cards


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IntelIntel--CPU Motherboard Diagram (ATX)CPU Motherboard Diagram (ATX)

CPU slot is

perpendicular

to the

expansion slots

and do notobstruct the

expansion

cards.


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AMD MotherboardAMD Motherboard


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Types of CPUTypes of CPU

Intel Processor Bus Speed(Mhz)

SocketUsed

AMDProcessors

Bus Speed SockedUsed

Classic Pentium 66 Socket 7 AMD K6 66 Slot A

PentiumMMX 66 Socket 7 AMD K7Athlon

100 - 133 Slot A

Pentium Pro 60,66 Socket 8 Duron 100 Slot APentium II 66,100 Socket

370,Slot 1

Celeron 66,100 Socket370

Pentium II Xeon 100 Slot 2

Pentium III 100,133 Slot 1

Pentium IIIXeon

100,133 Slot 2

Pentium IV 400 Socket423

What are the common CPU available?


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Older CPUsOlder CPUs

Model Speed

(bits)

Word Size

(bits)

Path Size

(bits)

Memory Address

(MB)

80386DX 40 32 32 1096

80386SX 33 32 16 16

486DX 60 32 32 4096

486SX 25 32 32 4096

First Pentium 60 32x2 64 4096


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CPU PackagesCPU Packages

1. Single EdgeCartridge (SEC)

Uses Slot 1, Slot 2 for Intel (Slot 2 for PII/IIIXeon)

Slot A for AMD and Duron

2. Pin Grid Arra(PGA)

So e PII, PIII, PI , Celeron, C ri

Socket (older CPU), Socket (Celeron & so ePII)

e er AMD and Duron

SEC T pe PGA T pe

What are the t pes of Package used b CPU?


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SupportingMultimediaSupportingMultimedia

How does the Intel CPU supportsMultimedia?Multimedia Extension technology(MMX)

What are the changes? 57 powerful new instructions

designed to manipulate and processvideo, audio and graphical dataefficiently

What are new enhancements? Single Instruction Multiple Data

(SIMD)

One instruction to perform thesame function on multiple pieces ofdata

Reduce compute-intensive loopscommon with video, audio, graphicsand animation

How does AM

D CPU supportMultimedia?

3DNow technology

What is 3DNow?

21 common instructions used in 3Dimaging

increased 3D performance


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Chipset and controllerChipset and controller

What is the system chipset andcontrollers?

Logic circuits that support the CPU

brain of the motherboard

What is its role in the PC?

Control data transfers betweenthe processor, cache, systembuses, peripherals--basicallyeverything inside the computer

Determines how fast and whichtype of processor, memory, andslots are used

Example of Chipsets?

Intel440BX, Intel 850, Intel 845

What are the supporting controllersbesides the System Chipset?

Keyboard controller:Manages notonly the keyboard but also theintegrated PS/2 mouse

"Super I/O" chip: Handles input

and output from the serial ports,parallel port, floppy disks, and insome cases, the IDE hard disks aswell

Additional built-in controllers:

Normally found in expansion cards:video, sound, network and SCSIcontrollers being the most common.


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Clock FrequencyClock Frequency

What are Clock frequency (Speed )?Speed at which a microprocessorexecutes instructions. Every computercontains an internal clock that regulatesthe rate at which instructions areexecuted and synchronizes all thevarious computer components

What are the clock speed that the PCuses?

1. External Clock frequency

2. Internal Clock Frequency

What is External Clock Speed?Also know as Bus Frequency. Suppliedby the Motherboard. The speedbetween the CPU is communicating withthe Chipset, RAM and Level 2 cache.

What is Internal Clock Speed?The speed inside the CPU

What is Clock Speed measured in?Megahertz (MHz)

What is the meaning of Clocking the

CPU? How is it done?It means setting the CPU to run at itscertified frequency. It is done bydoubling the External Clock frequencyby a multiplier.

What is over-clocking? How is it done?

It means setting the CPU to run at yourdesire speed. Note that running theCPU at higher speed may result inunstable CPU. More heat is generated,which the CPU may not tolerate.


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Calculating CPUs Clock SpeedCalculating CPUs Clock Speed

What is Bus speed (M

emory bus orsystem bus)?

Bus speed (external clock frequency) isdetermined by how much data can besent across the bus in 1 second

What are the 2 factors that use to

calculated CPU clock speed?Multiplier and bus speed

What the examples of multiplier?

2, 2.5, 3, 4, 5, 6

What are the common Bus speed?Bus can be set to operate at severalspeed 66Mhz, 75Mhz, 100Mhz, 133Mhzand 200 Mhz

How is CPU speed calculated?

Multiplier x Bus speed

Eg CPU speed = 150Mhz is 50Mhz x 3


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Memory CacheMemory Cache

What is function of cache memory? random access memory (RAM)

CPU access it more quickly than itcan access regular RAM.

Holds the information mostrecently used by the processor

How it works?

A processor is much more likely to needagain information it has recently used.This is the principle behind caching.

What are the types of cache found inthe PC?

Level 1 cache

Level 2 cache

Disk Cache

Peripherals cache


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Types of CacheTypes of Cache

What is Level 1 Cache? Primary cache. Fastest memory on the PC. Built directly into the processor

itself. This cache is very small,generally from 8 KB to 64 KB, andruns at the same speed as theprocessor

What is Level 2 Cache? Secondary cache to the level 1

cache larger and slightly slower To catch recent accesses that are

not caught by the level 1 cache 64 KB to 2 MB in size For older PC, found on mainboard For PII, found outside the CPU but

on the same PCB For PIII and above, found within

the PIII processor

What is Disk Cache?

A disk cache is a portion of systemmemory used to cache reads and writesto the hard disk

What is Peripherals Cache?

Much like the hard disk, other deviceseg. CD-ROM can be cached using thesystem RAM as well.


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BIOSBIOS

What does BIOS stand for?Basic Input/Output System

What is a BIOS?A special software that interfaces themajor hardware components of yourcomputer with the operating system.

Where is the BIOS stored?In a flash memory chip on themotherboard. Flash memory chip is atype of EEPROM.

What are the tasks perform by theBIOS when the PC is powered on?

Checks the CMOS Setup forcustom settings

Loads the interrupt handlers anddevice drivers

Initializes registers and power

management Performs the power-on self-test

(POST)

Displays system settings

Determines which devices arebootable

Initiates the bootstrap sequence

An AMI BIOS


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BIOS/CMOSBIOS/CMOS

What is Interrupt Handler?

Small pieces of software that act astranslators between the hardwarecomponents and the operating system.

Example of Interrupt Handler?

When you press a key on your keyboard,the signal is sent to the keyboardinterrupt handler, which tells the CPUwhat it is and passes it on to theoperating system.

How does BIOS optimises its own

performance?Since it is constantly interceptingsignals to and from the hardware, it isusually copied, or shadowed, into RAMto run faster.

What does CMOS stands for?

ComplimentaryMetal OxideSemiconductor

What is it?

Provides detailed information particularto your system and can be altered as

your system changes.

How does the BIOS work with CMOS?

Check the information stored in atiny (64 bytes) amount of RAM inCMOS

BIOS uses this information tomodify or supplement its defaultprogramming as needed

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Chpt3 the System Board