The Motherboard

1
The Motherboard
2
Objectives

• After completing this section you will
• Understand the major components on a motherboard
  including the microprocessor, chipset, math
  coprocessor, and expansion slots.
• Understand the basic operation of a
  microprocessor and what issues must be considered
  when upgrading it.
• Recognize and identify the microprocessor.
• Understand the differences among the various
  architectures and buses.
• Recognize different expansion slots.
• Recognize an adapters architecture or bus.

3
Microprocessor Overview

• Microprocessor (or processor)
• CPU (Central Processing Unit)
• Clones IBM compatibles
• PC Stands for Personal Computer, another name
  for the microcomputer.
• We will focus on compatibles (or non-Apple
  computers) because they make up the majority of
  computers in use today.
• Because Intel and AMD are the microprocessors
  primarily used in todays computer industry, they
  are the examples covered extensively in this
  material.

4
Microprocessor Basics

• Bit Either a 1 or 0. All microprocessors use 1s
  and 0s to calculate or interpret information.
• Byte Eight bits grouped together, the letter A
  looks like 01000001 to the processor. Each
  character on the keyboard appears as one byte (or
  eight bits) to the CPU. Denoted by the letter B,
  thirty-two bytes is 32B.
• Kilobyte Approximately 1,000 bytes (1,024
  exactly, but rounded off by the industry to the
  nearest thousand for ease of calculation). Shown
  as K or KB, ten kilobytes is shown as 10K or
  10KB.
• Megabyte Approximately one million bytes and
  referenced by M or MB. 540 megabytes is shown as
  540M or 540MB.
• Gigabyte Approximately 1 billion bytes
  (1,073,741,824) and written as 1G or 1 GB.

5
Microprocessor Basics
Motherboard Table 1
6
Microprocessor Basics

• Gigahertz (GHz) Hertz is a measurement of cycles
  per second (or frequency). One hertz equals one
  cycle per second. One megahertz (1MHz) is equal
  to one million cycles per second, one gigahertz
  (1GHz) is one billion cycles per second. For
  comparison, the 8088 microprocessor ran at 4.77
  MHz, todays CPUs run at over 2 GHz!
• Register size The number of bits processed at
  one time by the processor. Counted in multiples
  of 8 bits, such as 8-, 16-, and 32-bit register
  size. Sometimes referred to as word size by the
  computer industry. Intels 8086 processors word
  size was 16 bits or 2 bytes. Most microprocessors
  today have 64-bit or 128-bit register sizes.
• Bus Electronic lines to move the 1s and 0s
  inside the computer.

7
Microprocessor Basics

• Internal data bus Moves the 1s and 0s inside
  the microprocessor. In the 8086, there are 16
  separate electronic lines, each carrying one 1 or
  one 0. The word size and internal data bus were
  the same size, 16-bit.
• External data bus Used to connect the
  microprocessor to adapters, storage devices, and
  peripherals. Also called the external data path,
  these lines connect to ports and expansion slots.
  The Intel 8088 had an 8-bit external data bus.
  Todays CPUs have 64-bit external data paths.
• Todays microprocessors have 64-bit or 128-bit
  internal data bus lines and external data paths.

8
Microprocessor Basics
Internal and External Data Buses
Motherboard Figure 1
9
Microprocessor Basics
Intel Microprocessors
Motherboard Table 2
10
Microprocessor Basics

• Pipelines Separate (multiple) internal buses
  that operate simultaneously. This allows tasks
  and instructions to be broken down into smaller
  and more numerous parts, which permits the CPU to
  act on them more quickly and efficiently,
  improving computer performance.
• SEC (Single Edge Contact) cartridge Used with
  an Intel Slot 1 connector on Intels Pentium II
  microprocessor to reach speeds of 300MHz.
• SEPP (Single Edge Processor Package) cartridge
  Similar to the Pentium II SEC and used with the
  Intel Celeron processor.

11
Microprocessor Basics
Intel Microprocessors
Motherboard Figure 2
12
Microprocessor Basics
Motherboard Figure 3
13
Microprocessor Basics
Intel CPU Sockets and Slots
Motherboard Table 3
14
AMD Processors

• AMD (Advanced Micro Devices, Inc.) Produces a
  microprocessor similar to the Intel processors.
• Super 7 Socket Redesigned Socket 7 that allows
  for higher bus speeds (66 to 95 or 100MHz). Super
  7 motherboards allow higher CPU speeds, support
  for AGP and Ultra DMA hard drives, and have
  advanced power management features.
• Socket A 462-pin PGA socket for the AMD Athlon
  and Duron CPUs.
• Slot A Used by early AMD Athlon processors
  similar to Intel Pentium III, but they are not
  interchangeable.

15
AMD Processors
AMDs Socket A
Motherboard Figure 4
16
AMD Processors
AMD Athlon
Motherboard Figure 5
17
AMD Processors
AMD CPU Sockets and Slots
Motherboard Table 4
18
MMX, SSE, and 3DNOW!

• MMX A microprocessor technology from Intel that
  adds 57 instructions to an Intel processor to
  help with multimedia and communications software.
• SSE (Streaming SIMD Extensions) Intels
  processor technology that speeds up 3-D
  applications by allowing instructions to be used
  by multiple data items. There are 50 instructions
  allowing floating-point calculations to occur
  simultaneously.
• 3DNOW! 21 instructions and support for SIMD
  added to an AMD processor for 3-D applications.

19
Processor Speeds and Cooling

• Microprocessors and math coprocessors come in
  many speeds and this is measured in gigahertz
  (GHz). Hertz is a measurement of cycles per
  second (or frequency). One hertz equals one cycle
  per second. One megahertz (1MHz) is equal to one
  million cycles per second, one gigahertz (1GHz)
  is one billion cycles per second.
• The faster the microprocessor runs, the hotter it
  gets. Many processors now have heat sinks (metal
  bars protruding from the CPU to form a basic
  radiator) or small fans for cooling. In many
  cases, todays processors have both. Some systems
  even have multiple fans to prevent damage to the
  processor and internal components due to the
  amount of heat being generated.
• Liquid cooling system liquid is circulated
  through the system, including through a heat sink
  that is mounted on the CPU. It allows higher
  clock speeds and is quieter than a fan.

20
Processor Speeds and Cooling
Microprocessor Speeds
Motherboard Figure 6
21
Processor Speeds and Cooling
Microprocessor Fan and Heat Sink
Motherboard Figure 9
22
Processor Speeds and Cooling

• Other things to know when determining processor
  speeds
• Jumper Small metal connector with a plastic
  cover used to connect two metal pins together.
  Configuring the jumpers on a motherboard will
  change the settings on that board.
• Multiplier A number that is multiplied by the
  bus speed to determine the CPU speed.
• Example 60MHz bus speed x 1.5(multiplier)
  90MHz CPU

23
Processor Speeds and Cooling
CPU with Heat Sink and Fan
Motherboard Figure 10
24
Processor Speeds and Cooling
JP1 Jumper Block with Pins 1 and 2 Jumpered
Together
Motherboard Figure 11
25
Cache Memory

• Cache memory A fast type of memory designed to
  increase the speed of microprocessor operations.
• L1 (Level one) cache Cache memory that is
  located inside the microprocessor.
• Write-through cache The microprocessor writes
  1s and 0s into the cache memory at the same time
  as regular memory.
• Write-back cache The 1s and 0s are written to
  regular memory when the microprocessor is not
  busy. It is more efficient than write-through
  cache.
• L2 cache Cache memory that is on the
  motherboard for Pentium and lower processors.
  Starting with the Pentium Pro processor, the L2
  cache is inside the processor packaging and known
  as on-die cache.

26
Cache Memory

• L3 cache L1 and L2 cache are included with the
  processor packaging.
• COAST (Cache On A STick) Cache chips on the
  motherboard that resemble a small SIMM.
• DIB (Dual Independent Bus) Two buses used for
  the processor to communicate with motherboard
  components.
• FSB (front side bus) connects a CPU to the
  motherboard components.
• Back side bus connects the CPU to the L2 cache.

27
Cache Memory
Front Side Bus
Motherboard Figure 12
28
Microprocessor Study Guides
Intel Microprocessor Study Table
Motherboard Table 6
29
Microprocessor Study Guides
AMD Processors
Motherboard Table 7
30
Microprocessor Upgrade Overview

• Always refer to the motherboards documentation
  when upgrading the processor. It allows you to
  choose the proper processor and prevent damage to
  the processor and motherboard.
• VRM (Voltage Regulator Module) Provides the
  appropriate voltage for microprocessors. It is
  usually found on Socket 7 or Socket 8 for
  Pentiums.

31
Installing and Overclocking Microprocessors

• Always refer to the motherboard manuals for the
  installation steps to upgrade or install the
  processor. Your book contains general
  instructions for upgrading and installing the
  microprocessor beginning on page 2-25.
• Overclocking Changing the front-side bus speed
  or the multiplier to boost the CPU speed or
  system speed. This can cause damage to the CPU,
  motherboard, or other components.

32
Installing and Overclocking Microprocessors
Computer Case Auxiliary Fans
Motherboard Figure 14
33
Dual Processors

• Adding another (or dual) processor can greatly
  enhance computer performance. Most home and
  business users do not require an additional
  processor, however most servers do.
• Follow all manufacturers documentation on
  selecting an additional processor, installing it,
  and configuring the motherboard with dual
  processors.
• Its important to add RAM if possible when adding
  a second processor. Put in as much RAM as the
  customer can afford to improve performance. A
  general rule of thumb is to double the RAM when
  adding a second processor.

34
Motherboard Troubleshooting

• Motherboard and power problems are probably the
  most difficult things to troubleshoot. A good
  general list of motherboard troubleshooting tips
  can be found on page 2-29 in your book.

35
Expansion Slots

• Expansion slots allow adapters to be installed
  into the motherboard to add capabilities to the
  PC.
• Technicians must be able to identify expansion
  slots and distinguish between the adapters that
  use them.
• The technician must be able to install the proper
  adapter in the correct expansion slot and
  configure both correctly.

36
ISA (Industry Standard Architecture)

• ISA (Industry Standard Architecture) The oldest
  expansion slot that is configured in 8-Bit and
  16-Bit slots.
• Also referred to as the AT bus.
• Operates at 8MHz, although some manufacturers
  reliably achieve a throughput of 10 MHz.

Motherboard Figure 15
37
EISA (Extended Industry Standard Architecture)

• EISA (Enhanced Industry Standard Architecture)
  32-bit expansion slot that is the same length as
  an ISA slot and twice as deep.
• A non-proprietary architecture developed by a
  group of nine vendors in response to IBMs
  proprietary MicroChannel Architecture.
• A 32-bit, 10MHz standard that also allows ISA
  adapters to operate in the expansion slots.
• This standard was never as successful as the
  designers hoped.

38
PCI (Peripheral Component Interconnect)

• PCI (Peripheral Component Interconnect) The
  most popular expansion slot that is configured in
  both 32-bit, 33MHz and 64-bit, at 33MHz and
  66MHz.
• A new standard is the PCI-X which can operate at
  66MHz, 133MHz, 266MHz, and 533MHz. PCI-X 1066MHz
  is being developed.
• PCI adapters are configured with software and the
  standard supports bus-mastering, which allows an
  adapter to take over the external bus from the
  CPU and execute operations with another
  bus-mastering adapter without going through the
  processor.

39
PCI (Peripheral Component Interconnect)
PCI-X Block Diagram
Motherboard Figure 17
40
PCI (Peripheral Component Interconnect)
3.3 Volt and 5 Volt PCI Expansion Slots
Motherboard Figure 18
41
PCI (Peripheral Component Interconnect)
Motherboard Figure 19
42
Mini PCI

• Mini PCI 32-bit, 33MHz standard was developed
  to allow PCI upgrades and interface cards to be
  added to laptops, docking stations, and printers.
  Mini-PCI cards have 3 form factors Type I, Type
  II, and Type III.

Mini PCI Adapter
Installed in Laptop
Motherboard Figure 20
43
AGP (Accelerated Graphics Port)

• AGP (Accelerated Graphics Port) 32-bit bus
  interface for graphics adapters developed from
  the PCI bus.
• It speeds up 3-D graphics, 3-D acceleration, and
  full-motion playback.
• Allows the video adapter to directly access RAM
  on the motherboard when needed.
• The video subsystem is isolated from the rest of
  the computer.
• In order to implement AGP, the motherboard must
  have an AGP expansion slot, the chipset must
  support AGP, and an operating system that
  supports AGP must be installed.
• Some motherboards will allow changing the amount
  of memory AGP can use. The amount normally used
  is 64MB, configured through BIOS settings, and
  referred to as the AGP Aperture.

44
AGP (Accelerated Graphics Port)
AGP Versions
Motherboard Table 8
45
AGP (Accelerated Graphics Port)
AGP Expansion Slot
Motherboard Figure 22
46
More Motherboard Connectors

• AMR (Audio/Modem Riser) Connector on the
  motherboard for combination audio and modem
  adapters without taking up a PCI slot.
• CNR (Communications Network Riser) Intels
  design that allows the integration of network,
  audio, and modem functions. It shares a PCI slot
  and is located beside or between other
  motherboard expansion slots.
• ACR (Advanced Communication Riser) Technology
  that supports audio, modem, networking, and DSL
  modems. It was developed by a group of companies
  including AMD, VIA Technologies, Motorola, and
  3Com.

47
Future Buses

• HyperTransport AMDs futuristic I/O
  architecture in which a serial-link design allows
  devices to communicate in a daisy chain fashion.
• InfiniBand A futuristic I/O architecture
  wherein point-to-point device connections are
  made through a switching fabric.
• HCA (Host Channel Adapter) Connects memory to a
  switch fabric and is used in the InfiniBand bus
  architecture.
• TCA (Target Channel Adapter) An adapter that
  connects end devices to the switch fabric and is
  used in the InfiniBand architecture.
• RapidIO A futuristic I/O architecture that
  supports interconnections for chip-to-chip,
  board-to-board, and device-to-device.

48
Proprietary Expansion Slots

• Some older computers have an expansion slot built
  into the motherboard that are neither ISA nor
  PCI. These are proprietary expansion slots that
  only fit proprietary adapter cards. These are
  only available from the expansion slot
  manufacturer (if still supported) and usually
  expensive.

49
USB (Universal Serial Bus)

• USB (Universal Serial Bus) Allows connection of
  up to 127 external devices without degradation of
  speed. Can be used by many types of devices as
  long as the operating system supports USB.
• Original USB includes two speeds
• 1.5Mbps for keyboards and mice.
• 12Mbps for modems, CD/DVD drives, printers,
  scanners, monitors, and digital cameras.
• USB version 2.0 supports speeds up to 480Mbps for
  videoconferencing cameras, higher resolution
  printers and scanners. It is backward compatible
  for USB 1.1 devices.
• USB has two types of USB ports and connectors
  Type A and Type B.

50
USB (Universal Serial Bus)
USB Type A and Type B Connectors
Motherboard Figure 27
51
IEEE 1394 (FireWire or I.Link)

• IEEE 1394 known as FireWire and supports up to
  63 devices. It is able to support digital audio
  and video devices.
• Supports plug and play like USB and the devices
  are hot swappable.
• The IEEE 1394 bus is actually a peer-to peer
  standard meaning a computer is not needed to use
  it, such as connecting a digital camera directly
  to a hard drive to transfer picture files.
• Designed to support high-speed audio and video
  devices with greater throughput for applications
  such as video conferencing.
• All versions of IEEE 1394 support speeds of 100,
  200, 400, 800 or 1200 Mbps and a maximum distance
  of 236 feet or 328 feet for IEEE1394b.

52
IEEE 1394 (FireWire or I.Link)

• IEEE 1394 known as FireWire and supports up to
  63 devices. It is able to support digital audio
  and video devices.

Motherboard Figure 28
53
PC Card

• PC Card Previously known as PCMCIA (Personal
  Computer Memory Card International Association).
  It is used for modems, hard drives, network
  adapters, etc. in laptop computers.
• CardBus Allows 32-bit transfers at speeds up to
  33MHz.
• SmartMedia Holds pictures and audio files and
  is used with digital cameras, PDAs, etc.
• ZV port (Zoomed Video Port) Allows direct data
  transfer from a PC Card to a video controller.
  Data transfers over the ZV bus instead of the
  system bus.
• CardBay Allows laptop computers to be
  compatible with the USB and IEEE 1394 serial
  interfaces.

54
PC Card
PC Card
Motherboard Figure 30
55
PC Card
PC Cards
Motherboard Table 9
56
PC Card
Expansion Slot or Port Overview
Motherboard Table 10
57
Chipsets

• Chipset The principle chips on the motherboard
  that work in conjunction with the microprocessor
  and allow features on a computer.
• For example, they control
• Maximum amount of motherboard memory
• The type of RAM chips
• The motherboards capacity for multiple
  processors
• Support for the latest version of PCI

58
Types of Motherboards

• Form Factors The different sizes of
  motherboards.
• The most common motherboards are
• AT named after IBMs original AT computer
  motherboard.
• Baby AT smaller size of the AT.
• ATX similar to baby AT, but rotated 90 degrees.
• NLX designed around Pentium II and higher,
  allows more expansion.
• MicroATX max size is 9.6 inches by 9.6 inches,
  fits ATX case.
• FlexATX 9 inches by 7.5 inches and backward
  compatible with ATX and MicroATX.
• ITX 8.5 inches by 7.5 inches and made for a
  smaller power supply.
• WTX for large workstations and servers.

59
Types of Motherboards
NLX Motherboard
Motherboard Figure 24
60
Upgrading and Replacing Motherboards

• There are several issues to be taken into account
  when upgrading a motherboard
• Memory
• Adapter types
• Type of case
• Microprocessor
• Chipsets
• Hard drive
• Power supply
• Future upgrade-ability
• There is a basic guide on page 2-51