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Motherboard

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Section Objectives Define the purpose of the major components on a motherboard

including the CPU, chipset, and expansion slots Explain the basic operation of a microprocessor and what

issues must be considered when upgrading it Recognize and identify the motherboard, CPU and expansion

slots Compare and contrast motherboard buses and expansion slots Identify methods to add functionality to portable devices.

Explain different motherboard technologies such as MMX, HypterTransport, HyperThreading, and dual/quad-core

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Microprocessor Overview

- Microprocessor (or processor)

- CPU (Central Processing Unit)

- Clones – IBM compatibles

- PC – Stands for Personal Computer, another name for the microcomputer.

Intel and AMD are the microprocessors primarily used in today’s computer industry.

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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.

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Microprocessor Basics

Byte Table

Motherboard – Table 2.1

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Microprocessor Basics

• Gigahertz (GHz) – Hertz is a measurement of cycles per second (or frequency). One hertz equals one cycle per second. One gigahertz (1GHz) is one billion cycles per second.

• 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. Most microprocessors today have 64-bit or 128-bit register sizes.

• Bus – Electronic lines to move the 1s and 0s inside the computer.

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Microprocessor Basics

Internal data bus – Moves the 1s and 0s inside the microprocessor.

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.

Today’s microprocessors have 64-bit or 128-bit internal data bus lines and external data paths.

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Microprocessor Basics

Internal and External Data Buses

Motherboard – Figure 2.1

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Microprocessor Basics

Intel Microprocessors

Motherboard – Table 2.3

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Microprocessor Basics

ALU (Arithmetic Logic Unit) – Component of the processor which carries out calculations and comparison logic.

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.

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Microprocessor Basics

Motherboard – Table 2.4

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Microprocessor Basics

Motherboard – Figure 2.2

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AMD Processors

AMD (Advanced Micro Devices, Inc.) – Produces a microprocessor similar to the Intel processors.

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.

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AMD Processors

Motherboard – Figure 2.3

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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.

L2 cache – Cache memory that is inside the processor packaging but not

part of the CPU, also known as on-die cache.

L3 cache – Cache memory located in the CPU housing or on the

motherboard.

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Cache Memory

Motherboard – Figure 2.4

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Clocking

Clock Signal – Generated by the motherboard and used to control transfer of 1s and 0s to CPU.

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

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.

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Jumper

Motherboard – Figure 2.8

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Dual and Quad Processors

Dual-core CPU – Combines two CPUs on a single unit. Quad-core CPU – Either two dual-core CPUs installed on the

same motherboard or two dual-core CPUs installed in a single socket.

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AMD dual-core memory access

Motherboard – Figure 2.9

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Intel dual-core memory access

Motherboard – Figure 2.10

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Sockets and Slots

Different types of sockets:PGA (pin grid array) – even rows of holes around the square

socketSPGA (staggered pin array) – staggered holesPPGA (plastic pin grid array) – used on Intel Celerons and

Pentium 4sµPGA (micro pin grid array) – used by AMD Opterons and

various Athlon 64s LGA (land grid array) – used with AMD Opterons and Intel

Pentiums 4s and Xeons ZIF sockets (Zero Insertion Force) – processor sockets used

today

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LGA775 socket

Motherboard – Figure 2.11

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Processor Speeds and Cooling

Many processors now have heat sinks (metal bars protruding from the CPU to form a

basic radiator) and/or small fans. Some systems have multiple fans.

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.

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CPU fan and heat sink

Motherboard – Figure 2.12

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Installing Microprocessors

Always refer to the motherboard manuals for the installation steps to upgrade or install the processor. Your manual contains general instructions for upgrading and installing the microprocessor .

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Installing an AMD CPU

Motherboard – Figure 2.16

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Overclocking Microprocessors

Overclocking – Changing the front-side bus speed and/or the multiplier to boost the CPU speed or system speed. This can cause damage to the CPU, motherboard, or other components.

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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) – Intel’s processor technology that speeds up 3-D applications by allowing instructions to be used by multiple data items.

3DNOW! – 21 instructions and support for SIMD added to an AMD processor for 3-D applications.

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Expansion Slots

Expansion slots allow adapters to be installed into the motherboard to add capabilities to the PC.

You must be able to identify expansion slots and distinguish between the adapters that use them.

You must be able to install the proper adapter in the correct expansion slot and configure both correctly.

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Motherboard expansion slots

Motherboard – Figure 2.17

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ISA (Industry Standard Architecture)

ISA (Industry Standard Architecture) – The oldest expansion slot, is configured in 8-Bit and 16-Bit slots.

Motherboard – Figure 2.18

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PCI (Peripheral Component Interconnect)

PCI (Peripheral Component Interconnect) – The previously popular expansion slot. It 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, 533MHz, and 1066MHz.

Figure 2.19 Figure 2.22

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AGP (Accelerated Graphics Port)

AGP (Accelerated Graphics Port) – Bus interface for graphics adapters developed

from the PCI bus.

It speeds up 3-D graphics, 3-D acceleration, and full-motion playback.

The video subsystem is isolated from the rest of the computer.

Allows the video adapter to directly access RAM on the motherboard when

needed.

Figure 2.23

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PCI-E (Peripheral Component Interconnect-Express)

PCI-E(Peripheral Component Interconnect-Express) – Also known as PCIe. PCI-e is replacing PCI, PCI-X, and AGP expansion slots.

Hypertransport – Technology used by AMD, which is a high-speed bus used to connect multiple CPUs, interface and AMD CPU with input/output devices, interface the CPU with PCI, PCI-X, and PCI-E slots, and interface the CPU with RAM.

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PCI for the Laptop

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.

ExpressCard® – Latest high-performance, hardware expansion standard for mobile computers. Replaces PC cards. Provide the user the ability to add a variety of plug‘n play applications.

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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) – Intel’s 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.

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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.

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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 motherboard’s capacity for multiple processors– Support for the latest version of PCI

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Types of Motherboards

Form Factors – The different sizes of motherboards. The common motherboards are:

– ATX: most common motherboard

– Different types of ATX include: microATX, miniATX, and FlexATX

Older form factors: AT, Baby AT, NLX, ITX, WTX

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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

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Motherboard Troubleshooting

• Motherboard and power problems are some of the most difficult to troubleshoot. One of the most beneficial tools for troubleshooting the motherboard is POST.