CPUs and motherboards

Unit objectives Describe features and functions of CPUs,

classify CPUs according to their specifications, and replace a CPU

Describe the techniques used to cool CPUs and other components in a PC, and replace a system fan

Describe motherboards, their components, and form factors, and replace a motherboard

Identify the symptoms of, probable causes of, and potential solutions to problems with motherboards and CPUs

Topic A

Topic A: Central processing units Topic B: Cooling techniques Topic C: Motherboards Topic D: Motherboard and CPU

troubleshooting

Central processing unit (CPU)

“Brains” of your PC Processes instructions, manipulates data,

controls interactions of other circuits Contains:

– A control unit– One or more

execution units– Single-core vs.

multi-core processors– Registers

CPU performance

Instruction — Low-level, hardware-specific command

Rated in millions of instructions per seconds (MIPS)

Rated according to clock speed Older CPUs — One clock cycle/

one instruction Newer CPUs — One clock cycle/

many instructions

CPU design characteristics

Addressable RAM Branch prediction Address bus Data bus Internal bus Cache Clock speed Dual Independent Bus (DIB) Front-side bus speed

continued

CPU characteristics, continued

Hyperthreading Multimedia extensions (MMX) Multiprocessing Out-of-order completion Overclocking Pipelining Register renaming Single Instruction Multiple Data

(SIMD)continued

CPU characteristics, continued

Speculative execution Superpipelining Superscalar Throttling

Multiple-processor support

Requires symmetric multiprocessing code for OS and applications

Symmetric multiprocessing code is included in:– Windows 2000 Professional

– Windows XP Professional

– Windows Vista Business, Ultimate, Enterprise

– 32-bit versions of Windows 7

Linux and Linux applications are available in symmetric multiprocessing versions

64-bit versions of Windows 7 use NUMA

Processor specifications

Manufacturers:– Intel– AMD– Centaur Technology– Elbrus International – Integrated Device Technology, Inc. (IDT)– SIS (Silicon Integrated Systems)– ST Microelectronics

Primary specifications Bus width specifications Internal specifications

Activity A-1

Identifying CPUs

Inside the case

Chipsets CPU packaging Slots Cooling techniques

Chipsets

Memory control System bus functions Audio functions Video display functions System management functions

Northbridge and Southbridge

Two most important components of a PC chipset

Northbridge controls interactions between the CPU, memory, AGP video control circuitry, and the Southbridge

continued

Northbridge/Southbridge, continued

Southbridge controls interactions between buses and devices not controlled by the Northbridge– PCI expansion bus– Floppy drive controller– Serial port– Parallel port– PS/2 keyboard and mouse ports

CPU packaging

Chip = die A package is made up of

– Die– Plastic, metal, or ceramic case– Wires or connectors– Support chips– Cooling components

PGA package

80486

SECC package

Pentium 3

Package Full name Description Processors

PDIP Plastic dual inline package

Die is encased in plastic. Large, flat, metal pins are inserted into socket that’s soldered to motherboard.

8080, 8086, 8088

PGA Pin grid array Rows of pins extend from bottom of package. Nickel-plated copper slug sits atop the die to improve thermal conductivity. Pins are arranged so that chip can be inserted in just one way.

80286 (68 pins), 80386 (132 pins), 80486 (168), and Xeon (603 pins)

CPGA Ceramic pin grid array

Uses a ceramic substrate with pins arranged in a pin grid array.

AMD Socket A Athlons and the Duron

SPGA Staggered pin grid array

Similar to PGA, but pins are staggered to fit more in a given area.

Pentium, Pentium MMX, Pentium Pro with 387 pins

Packages

continued

Package Full name Description Processors

PPGA Plastic pin grid array

Updated version of SPGA package.

Pentium Pro; early Celeron processors; Pentium III with 370 pins

FC-PGA Flip chip pin grid array

Similar to PGA, but die is exposed on top. Enhances heat transfer and cooling options.

Pentium III and Celeron with 370 pins; 423-pin version used with Pentium 4 processors

FC-PGA2 Flip chip pin grid array 2

Similar to FC-PGA, but with integrated heat sink, connected to the die during manufacturing.

Pentium III and Celeron with 370 pins; 478-pin version used with Pentium 4 processors; 469 version used with AMD Athlon Thunderbird processors

OOI OLGA On Interpreter

Die mounted face-down, as with FC-PGA, for better cooling, but uses different pin arrangement.

423-pin Pentium 4

Packages, continued

continued

Package Full name Description Processors

OPGA Organic pin grid array

Silicon die is attached to organic plastic plate, which is pierced by array of pins to make connections to socket. Cheaper, thinner, and lighter than ceramic package. Reduces electrical impedance.

AMD Athlon XP

SECC Single Edge Contact Cartridge

Mounts CPU vertically on motherboard. Uses an edge connector similar to an adapter card’s. Die is covered with metal case. Metal thermal plate mounted to back of cartridge acts as heat sink.

Pentium II processors with 242 contacts; Pentium II Xeon and Pentium III Xeon processors with 330 contacts

SECC2 Single Edge Contact Cartridge 2

Similar to SECC, but without thermal plate.

Later versions of the Pentium II and III processor with 242 contacts; AMD Athlon K7

Packages, continued

continued

Package Full name Description Processors

SEP Single Edge Processor

Similar to SECC but without metal case.

Early Celeron processors with 242 contacts

FCBGA Flip chip ball grid array

Similar to FC-PGA, but uses balls for contacts. Balls can’t be bent.

Xeon, plus many support chips in current Pentium-class computers

LGA Land grid array

Has small raised contacts. Corresponding socket has pins that meet the contacts. A very high-density package.

Celeron D, Pentium 4, Pentium 4 D, Pentium Extreme Edition, Core2 Duo, Core2 Extreme

Packages, continued

Sockets and slots

continued

Type Supports these packages

Processors Notes

Slot A AMD’s Card Module package

AMD Athlon Wasn’t a popular design; didn’t last long.

Socket A (Socket 462)

SPGA with 462 pins AMD Athlon and Duron

Eleven holes in socket were plugged to ensure that packages were installed correctly.

Socket 5 PGA, SPGA with 320 pins

Pentium

Socket 7 PGA; SPGA with 321 pins; PGA, SPGA, and FC-PGA with 296 pins

AMD K5 and K6, Cyrix 6x86, Pentium, and Pentium MMX

First socket to support dual voltage inputs. Prevents a new CPU from being plugged into a Socket 5 socket.

Sockets and slots, continued

continued

Type Supports these packages

Processors Notes

Socket 8 387-pin PGA, SPGA, and FC-PGA

Pentium Pro Short-lived socket design used primarily with Pentium Pro.

Socket 423

423-pin SPGA and FC-PGA, OOI

Pentium 4 Short-lived socket design used for early Pentium 4 processors.

Socket 478

FC-PGA2 Celeron, Pentium 4, Pentium D, Pentium Extreme Edition

Current general-purpose socket for Pentium-class processors.

Socket 370

SPGA and PPGA with 370 pins

Celeron, Celeron II, Pentium III

Similar to Socket 7 design, with 6 staggered rows of pins rather than 5.

Type Supports these packages

Processors Notes

Slot 1 SECC, SECC2, SEP with 242 contacts

Pentium II, early Celeron, and Pentium III

Edge connector slot developed specifically for SECC, SECC2, and SEP packages.

Slot 2 SECC, SECC2, SEP with 330 contacts

Pentium II and Xeon

Similar to Slot 1, but CPU can communicate with Level II cache at full CPU speed.

LGA775 (Socket T)

LGA Celeron D, Pentium 4, Pentium D, Pentium Extreme Edition, Core2 Duo, Core2 Duo Extreme

Designed to work specifically with new high-density LGA package. Intel’s current high-end socket.

Sockets and slots, continued

Pentium with MMX CPU & Socket 7 socket

Activity A-2

Identifying your CPU’s socket and package type

CPU installation

CPU typically replaced as part of new motherboard

Add another CPU to multiprocessor motherboard

CPU packaging must match slot or socket in motherboard

CPU packages held in place by retaining clips, locking lever, or other mechanism

CPU retaining clips

Clip Clip

Installing a CPU

1. Unplug the computer and open the case

2. Remove the old CPU

3. Store the old CPU

4. Insert the new CPU package into its socket and secure it with the retaining mechanism

5. Close the case, reconnect cables, and boot the PC

Activity A-3

Replacing a CPU (optional)

Topic B

Topic A: Central processing units Topic B: Cooling techniques Topic C: Motherboards Topic D: Motherboard and CPU

troubleshooting

Typical cooling mechanisms

Fans Heat sinks and cooling fins Heat pipes Water pumps Peltier coolers Undervolting

Power supply and CPU fans

Power supply fan

CPU fan

Cooling fins

Cooling fins and a fan

Other cooling techniques

Heat pipes — Small tubes filled with fluid Water pumps — Tubes filled with water,

moved away from CPU to outside case and through cooling fins

Peltier coolers – Electronic device that gets colder when voltage

is applied– Non-convection– Connected directly to CPU– Can be combined with water coolers

continued

Other cooling techniques, continued

Phase-change cooling– Vapor compression– Gas to liquid– Liquid absorbs processor heat and evaporates– Gas returned to compressor– Cycle begins again– More efficient than water cooling systems– Generate significant noise

Undervolting– Less power; less heat– Can cause system problems

Activity B-1

Examining the cooling systemsin your PC

Activity B-2

Replacing a system fan

Topic C

Topic A: Central processing units Topic B: Cooling techniques Topic C: Motherboards Topic D: Motherboard and CPU

troubleshooting

A motherboard

Main circuit board

Motherboards

Components reviewCPU

Expansion slots

Graphics adapter slot

Hard drive interface connectors

Floppy drive interface connector

Optical drive interface connector

Power connector

Memory slots

PS/2 mouse and keyboard ports

USB port

IEEE 1394 / FireWire port

Serial port

Parallel port

Battery

Network interface and modem

Video connectors

Daughter board

A circuit board Connects to another circuit board to

provide or assist with its functions Most often used with video cards

Riser card

Riser card with expansion slots

Motherboard

Connector between the two

Form factor

Size and shape of a motherboard Dictates power supply and case Describes physical layout of

components

Activity C-1

Examining motherboard components and form factor

Motherboard installation

Failures from manufacturing defects or rough handling

Replaced due to failure; upgrades; building PC from scratch

Held in place by screws or plastic clips Remove wires, cables, connectors,

and other system components, such as power supply and drives

Installing a motherboard

1. Unplug the computer and open the case

2. Disconnect all wires from old motherboard

3. Remove the power supply and drives

4. Remove the old motherboard

5. Store the old motherboard

6. Install the new motherboard

7. Reinstall the power supply and drives

8. Connect all wires

9. Close the case, reconnect cables, and boot the PC

Activity C-2

Replacing a motherboard (optional)

Topic D

Topic A: Central processing units Topic B: Cooling techniques Topic C: Motherboards Topic D: Motherboard and CPU

troubleshooting

Motherboard and CPU problems

System fails to boot Burning or foul odor or smoke comes out of

the case Fans come on and power lights indicate that

power is present, but system fails to boot Video display problems occur on system

with integrated display adapter Intermittent problems occur that can’t be

traced to failure of other components

Activity D-1

Troubleshooting motherboard andCPU problems

Unit summary

Described features and functions of CPUs, classified CPUs according to their specifications, and replaced a CPU

Described the techniques used to cool CPUs and other components in a PC, and replaced a system fan

Described motherboards, their components, and form factors, and replaced a motherboard

Identified the symptoms of, probable causes of, and potential solutions to problems with motherboards and CPUs