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Computer Fundamental

Lecture 5

Computer SystemHardware Components (I)

Computer CaseMotherboardCPU

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Computer System Overview

Computer System = Hardware + Software

The operating system (OS) is the software that controls functionality and provides lower-level routines for application programs.

Most operating systems provide functions to read and write data to files.

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An operating system translates requests for operations on files into operations that the disk controller can perform. The operating system helps the computer perform four basic operations

• Input / Ouptut• Processing• Storage

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Hardware Components (Personal Computer) Power Supplies and Computer Cases / Chassis Motherboard CPU (Central Process Unit) / Processor Cache Memory Memory (RAM / DRAM) BIOS / Flash ROM Bus and expansion slots (expansion card e.g. sound card, SCSI card) Video/Graphics Cards and Monitors Different types of I/O Port (serial port, parallel port, USB port, Firewire) Storage Devices (Floppy, Hard Drive, CDROM, DVDROM, USB Flash) Modem and Network Interface Cards (NICs) Wireless Devices (Wireless LAN card, Bluetooth, IrDA) Mouse / Keyboard

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Computer Cases – Tower ATX

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Computer Cases - Desktop

ATX

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Desktop model – sits on a desk horizontally. The monitor can be set on top of the case. This choice can be a space-saver.

Tower model – Stands upright in a vertical position that allows easy placement on the floor. Mini-tower, mid-tower and full-tower cases are available.

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Rack Mounted Server 1U = 44.45 mm (1.75 in)

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Computer Cases (cont.)

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Typical back panel layouts

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AT (Advanced Technology) form factor Specified motherboard dimensions of 12” x 13.8” Utilized by IBM AT PC in the 1980s

Baby AT form factor Specified motherboard dimensions of 13” x 8.7” Industry standard form factor from 1993 to 1997

ATX form factor Specified motherboard dimensions of 12” x 9.6” Open specification that is most commonly used today Includes all AT voltages plus a +3.3-volt circuit

A+ Guide to Hardware, 4e 13

Types of Form Factors

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MicroATX form factor Reduces number of I/O slots on the motherboard

BTX (Balanced Technology Extended) form factor Focuses on reducing heat and supporting motherboard

LPX and Mini-LPX form factors Designed for low-end PC motherboards

NLX form factor Developed to improve the LPX form factor

Backplane Systems (Active and Passive) Use boards with slots, but little or no circuitry

A+ Guide to Hardware, 4e 14

Types of Form Factors

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Power Supply - Components

Case and cover Power cord Voltage selector (i.e. 110V or 230V) Power switch Power converter Motherboard power connector Disk drive power connectors Fan Fuse

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Motherboard Power Connector

Disk Drive Power Connector

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Factors to Consider When Selecting a Power Supply

Factor ExplanationWattage In order to upgrade the PC with more equipment or faster

processors, the power supply must provide enough power to the equipment without becoming overloaded.http://extreme.outervision.com/psucalculator.jsp

Form factor (E.g. ATX, MicroATX)

Depending on the type of case and motherboard selected, the power supply must adhere to the same form factor requirement as these items in order to fit inside the case and correctly power the motherboard and other devices.

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Factors to Consider When Selecting a Power Supply

Factor RationaleCPU type Different CPUs require different voltages. For example

some AMD chips and motherboards require more power than certain Intel chips and vice versa.

Expandability If the power supply only has enough power to supply the current CPU, motherboard, and devices, there might not be enough power to supply any upgrade to the system.

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Factors to Consider When Selecting a Power Supply

Factors Rationale

Energy efficiency

If the power supply has an efficiency rating. The higher the rating, the lower the heat generated by the power supply when converting voltage.

Fan type andDirection

The power supply must have a high-quality fan, because the fan is the primary source of airflow inside the case. Some fans can change direction to allow air to be blown directly on the CPU and to regulate the quality of the air entering the case.

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Factors to Consider When Selecting a Power Supply

Factors Rationale

Control signals

Modern power supplies can be regulated by the motherboard. The main board can regulate the speed of the fan, depending on the temperature inside the case. The board can also turn off the fan to save power, and some ‘smart’ power supplies can turn off the computer in the event of a fan failure before the components overheat.

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Factors to Consider When Selecting a Power Supply

Factors RationaleFault tolerance

If you have a PC that needs to be on at all times, consider using a dual power supply. If one unit fails, the other one takes over. Some design enable a power supply to be replaced while the computer is still powered.

Line conditioning

One way to ensure that the DC voltages supplied to the PC are kept at normal levels when spikes or brownouts occur is to install a power supply that has built-in conditioning. These units ensure that the DC voltages supplied to the system remain stable, even when the incoming AC current is not.

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Cooling Systems

The power supply fan helps prevent the computer components from overheating by maintaining airflow in the case.

A heat sink is made of a material that absorbs generated heat. It is designed to disperse the heat away from the CPU

Computer cases made of aluminum create a much cooler environment for the installed components.

Liquid cooled cases - They introduce water as a cooling agent. Liquid cooling units fit most cases that have a place to mount a back exhaust fan.

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MotherboardThe motherboard is also called the system board or the main board. Everything else in the system plugs into, is controlled by, or depends on the motherboard to communicate with other devices on the system. The system board is the largest of the printed circuit boards. Every system has one. The system board generally houses the following components:

The CPU The controller circuitry The Bus The RAM The expansion slots for

additional boards The ports for external

devices

The Complementary Metal-Oxide Semiconductor (CMOS)

The other Read Only memory (ROM)

The BIOS chips

The support chips providing varied functionality

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I/O PortsWhat kinds of device can be connected to the USB ports?

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I/O Ports

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Motherboard ComponentsComponents Description

Chipset(North Bridge + South Bridge)

A chip set is a set of chips on the motherboard that collectively controls the memory cache, external bus, and some peripherals.

CPU interface The socket or slot that the CPU connects to on the motherboard.

Expansion slots Receptacles [容器 ] on the motherboard that accept printed circuit boards. All computers have expansion slots that allow additional devices to be added.

Dip switches/jumpers

Used to change various aspects of how the motherboard is configured.

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Motherboard Components (Cont)Components DescriptionI/O Ports Connectors for input and output devices controlled by the

main board.

Internal buses Channels for data to move between the devices attached to the system, and to the CPU and its components.

Power supply socket

The connection for the power supply that provides power to the motherboard.

BIOS chip Provides the computer with the basic instructions to start up and check the hardware fro errors

Battery Keeps system time and provides a way for the BIOS to remember certain settings.

RAM sockets Connectors for inserting memory chips

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The Chipset A chipset is a set of chips on the motherboard that collectively controls

the memory cache, external bus, and some peripherals.

e.g. Intel P35 Intel P43/P45

CPU

NorthBridge

SouthBridge

ISA

Slot

PCI

Slot

PCI BUS

RAM

VideoRAM

AMR

IDEUSB

Chip Set

Major Chipset Manufacturers: Intel, SiS, nVidia, ATI and ALi

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North Bridge and South Bridge The north bridge is the chipset on your motherboard used to control data

communication and control signals to and from the CPU, Memory, Onboard Graphics / AGP Slot. These are the most important components of your computer .

The south bridge incorporates a number of different controller functions. It looks after the transfer of data to and from the hard disk and all the other I/O devices, and passes this data into the link channel which connects to the north bridge. With the new motherboards it should also handle PCI express slots. Also it manages USB and RAID controllers on the board.

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North Bridge

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North Bridge

The north bridge chip, also called MCH (Memory Controller Hub) / GMCH (Graphics and Memory Controller Hub) in Intel is connect directly to the CPU and has basically the following functions:

• Memory controller (*) • AGP bus controller (if available) • PCI Express x16 controller (if available) • Interface for data transfer with south bridge

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South Bridge

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South BridgeThe south bridge chip, also called ICH (I/O Controller Hub) is connected to the north bridge and is in charge basically of controlling I/O devices and on-board devices, e.g.• Hard disk drive ports (Parallel and Serial ATA ports) • USB ports • On-board audio (*) • On-board LAN (**) • PCI bus • PCI Express lanes (if available) • Real time clock (RTC) • CMOS memory • Legacy devices like interrupt controller and DMA controller

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ROM BIOS BIOS manages the startup process (startup BIOS) and

many basic I/O functions of the system (system BIOS). BIOS manufacturer

American Megatrends Inc. (AMI) Phoenix Technologies IBM

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Different Types of ROM EPROM – ROM chips that can be erased and reprogrammed. Erasable

programmable read-only memory (EPROM) is a special types of programmable read-only memory that can be erased by shining ultraviolet light through a clear windows on the top of chip.

EEPROM – Electrically erasable programmable read-only memory (EEPROM) chips are erased using a higher-than-normal electric voltage instead of ultraviolet light. (When the system BIOS or firmware is contained on EERPOM, it can be upgraded (reprogrammed) by running special instructions.

Flash ROM – Special EEPROM chips that have been developed as a result of advancements in EEPROM technology. Flash ROM holds the firmware, or BIOS in most new systems. It can be reprogrammed under special software control. Upgrading the BIOS by running special software is known as flashing. The BIOS implemented on a Flash ROM is known as Plug and Play BIOS, and it supports Plug and Play devices. These chips retain data when the computer is powered down so information is permanently stored.

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CMOS (Complementary Metal Oxide Semiconductor)

A battery-powered storage chip located on the system board. Stores the system startup configuration and parameters.

CMOS stores the master configuration for all components in the system.

The CMOS chip has rewritable memory since the configuration data can be changed or updated as the components or devices in the computer are changed.

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CMOS – configuration parameters Boot Sequence Date / Time Type of Floppy Disk Drive / LS120 Default display (e.g. VGA) RAM Wait State System Clock Rate / Bus Frequency Setting Hard Drive Type Microprocessor Type Core-to-Bus Speed Ratio Core Voltage Level …….

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CMOS – configuration parameters

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CMOS – configuration parameters

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CMOS – configuration parameters

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Central Processing Unit (CPU)Major components:

Arithmetic and Logic Unit (ALU) – The ALU performs both arithmetic and logical operations. Arithmetic operations are fundamental math operations like addition, subtraction, multiplication, and division. Logical operations such as AND, OR and XOR make comparisons and decisions, and these determine how a program is executed (For modern CPU, it may have two or more ALU).

Control Unit (CU) – The control unit instructs the rest of the computer system on how to follow a program’s instructions. It directs the movement of data to and from processor memory.

Internal CPU Bus, which is responsible for data /control signal transfer between the various units (e.g. ALU, registers and control unit).

Registers, which are temporarily storage within the CPU (e.g. instructions and data)

Remark:

Major manufacturers: Intel and AMD

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CPU

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Registers with specific functionsRegisters within the CPU Program Counter (PC)

Contains the address of the next instruction to be fetched from memory

Intel uses the name Instruction Point (IP) Instruction Register (IR)

Contains the opcode (or instruction) being executed Memory Address Register (MAR)

hold the address of next memory operation (load or store) For Intel CPU, source index register (SI) and Destination Index Register (DI) are used as MAR

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Registers with specific functions Memory Buffer Register (MBR)

hold the content of memory operation (e.g. DX register of Intel CPU)

Status Register / Flag Register Contain condition codes plus other status information. e.g. Sign, Zero, Carry, Equal, Overflow, Interrupt...

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CPU Processor Socket Types / Slot Types

It is a descriptive term for the way certain processor plug into a computer motherboard so that the processor makes contact with the motherboard’s built-in circuitry or data bus.

Examples: Socket T LGA 1366 for Intel Quad Core Socket T LGA 1156 for Intel Core i7 Socket T LGA 775 for Intel Celeron Dual-Core Socket 478 for Intel Pentium 4 Socket AM3 for AMD Phenom II / Athlon II Socket AM2+ for AMD Athlon X2

Processor Speed Rating It is the specifications that indicate the maximum (reliable) operating

speed at which the CPU can execute instruction e.g. 3.0 GHz

Note: The CPU speed and the frequency of the clock signal are not always at a one-to-one ratio. This is because the CPU can run at a much higher speed than the other chips on the motherboard. A variable-frequency synthesizer circuit, built into the motherboard circuit, multiplies the clock signal so that the motherboard can support several speeds of CPUs.

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Terminology for CPU System bus frequency or speed

Faster than other buses; e.g., 1066 MHz, 800 MHz Processor frequency or speed

Refers to speed of internal operations; e.g., 3.2 GHz System bus frequency x multiplier = processor frequency Overclocking: running processor at excessive speed Throttling: decreasing speed when overheating occurs Data path size and word size

Data path: transports data into processor (bandwidth of FSB) Word path: number of bits processed in one operation E.g. For the Intel Pentium processors, the data path size of FSB is 64

bits and the word size is 32 bits respectively.

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Terminology for CPU

Multiprocessing Simultaneous processing by two or more ALUs

Multiprocessor platform Contains two or more processors

Dual-core processing Processors share system bus, but have separate cache

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CPU Slot and Sockets A slot or socket is the physical connection used to attach the CPU to the

motherboard. The type of socket or slot supplied by the motherboard for the processor

must match that required by the processor.

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CPU Slot and Sockets

Connector Name Used by CPU Number of Pins VoltageSocket 423 Pentium 4 423 pins 39x39

SPGA grid1.7V and 1.75V

Socket 478 Pentium 4 478 pins in a dense micro PGA (mPGA)

1.7V and 1.75V

Socket PAC418 Itanium 418 pins 3.3V

PAC611 Itanium 2 611 pins 3.3V

Socket 603 Xeon DP and MP 603 pins 1.5 and 1.7V

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Example

SCEE Package

Slot 1 Connector

PGA Package

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CPU Speed

The CPU’s speed is the frequency at which it executes instructions. This frequency is measured in millions of cycles per second, or megahertz (MHz); or billions of cycles per second, or gigahertz (GHz).

The CPU has an internal and an external speed. The external speed corresponds with the motherboard’s speed, based on its system crystal. Each pulse (generated by system crystal in motherboard) is called a clock tick. The CPU’s internal speed is usually a multiple of that, so that multiple operations occur internally per clock tick.

A CPU’s speed as described in its specifications is its internal speed. (Note: Internal speed = Multiplier x External Speed)

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CPU Cache

Each CPU has at least two caches: L1 and L2. The L1 cache is built into the CPU on modern systems. It is the front-side cache, where data waits to enter the CPU.

The L2 cache, or back-side cache, is where data exiting the CPU waits. On modern systems, the L2 cache is within the CPU’s packaging but not integrated into the CPU’s die. On older systems, the L2 cache was on a separate set of chips on the motherboard. You can compare one CPU to another according to the size of its L1 and L2 caches.

Some newer systems also have an L3 cache. It sits between the CPU and RAM to optimize data transfer between them.

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CPU Voltage A CPU’s voltage is the amount of electricity provided to it by the

motherboard. Older CPUs have higher voltages (around +5V); newer ones have lower voltages (less than +2V in some cases).

One reason a given motherboard cannot support many different CPUs is that it must provide the correct voltage.

To get around this issue, some motherboards have voltage regulator modules (VRMs) that are able to change the voltage based on the CPU.

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What is Overclocking

In some system, the processor speed can be set higher than the rating on chip; this called overclocking the chip.

By overclocking, you are using the margin and running the chip closer to its true maximum speed.

Overclocking might enable you to get 10%-20% or more performance from your system.

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CPU Technology – Hyper-Threading

Intel’s Hyper-Threading (HT) Technology allows a single processor to handle two independent sets of instructions at the same time.

HT Technology converts a single physical processor into two virtual processors.

HT Technology is present in all Pentium 4 with 800 MHz CPU bus speed (2.4 GHz up through 3.8 GHz) as well as the Pentium 4 Extreme Edition and the dual-core Pentium Extreme Edition.

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How Hyper-Threading Technology Works

Internally, an HT-enabled processor has two sets of general-purpose registers, control registers, and other architecture components, but both logical processors share the same cache, execution units and buses.

During operation, each logical processor handles a single thread (the most basic unit of a running program).

Although the sharing of some processor components means that the overall speed of an HT-enabled system isn’t as high as a true dual-processor system would be, speed increases of 25% or more are possible when multiple applications or a single multithreaded application is being run (e.g 4 copies of IE).

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CPU Technology – Dual-core Technology HT Technology is designed to simulate two processors in a single

physical unit. Many applications do not support HT Technology and slow down when HT Technology is enabled.

A dual-core processor contains two processor cores in a single processor package.

A dual-core processor provides virtually all the advantages of a multiple-processor computer at a cost lower than two matched processors.

Both AMD and Intel introduced dual-core x86 compatible processors in 2005 (AMD – Athlon 64 X2, Intel – the Pentium Extreme Edition).

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Dual Core (AMD CPU)

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Intel Core Duo architecture

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Intel Core Duo Intel Core Duo

32-bit processor Two cores on one die 2 MB L2 cache by both cores Arbiter bus controls both L2 cache and FSB access

Intel Core 2 Duo 64-bit processor More L2 cache (2 MB to 6 MB)

Intel Core i3, i5, i7 Low-level (i3), Mid-range (i5), high-end performance (i7) DDR3 memory controller L3 cache

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Intel Core processor familyBrand

Desktop Laptop  

Code-named Cores Fab Date released Code-named Cores Fab Date released  

Core Solo Desktop version not available Yonah 1 65 nm Jan 2006  

Core Duo Desktop version not available Yonah 2 65 nm Jan 2006  

Core 2 Solo Desktop version not available Merom-LPenryn-3M

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65 nm45 nm

Sep 2007May 2008  

Core 2 DuoConroeAllendaleWolfdale

222

65 nm65 nm45 nm

Aug 2006Jan 2007Jan 2008

MeromPenryn

22

65 nm45 nm

Jul 2006Jan 2008  

Core 2 Quad KentsfieldYorkfield

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65 nm45 nm

Jan 2007Mar 2008 Penryn 4 45 nm Aug 2008  

Core 2 ExtremeConroe XEKentsfield XEYorkfield XE

244

65 nm65 nm45 nm

Jul 2006Nov 2006Nov 2007

Merom XEPenryn XEPenryn XE

224

65 nm45 nm45 nm

Jul 2007Jan 2008Aug 2008

Core i3 Clarkdale 2 32 nm Jan 2010 Arrandale 2 32 nm Jan 2010  

Core i5 LynnfieldClarkdale

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45 nm32 nm

Sep 2009Jan 2010 Arrandale 2 32 nm Jan 2010  

Core i7BloomfieldLynnfieldGulftown

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45 nm45 nm32 nm

Nov 2008Sep 2009Jul 2010

ClarksfieldArrandale

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45 nm32 nm

Sep 2009Jan 2010  

Core i7Extreme Edition

BloomfieldGulftown

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45 nm32 nm

Nov 2008March 2010 Clarksfield 4 45 nm Sep 2009  

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Advanced Intel Microprocessor Technologies

Intel Execute Disable Bit virus protection (XD bit) Execute Disable Bit allows the processor to classify areas in memory

by where application code can execute and where it cannot. When a malicious worm attempts to insert code in the buffer, the processor disables code execution, preventing damage and worm propagation.

Intel's Execute Disable Bit¹ functionality can help prevent certain classes of malicious buffer overflow attacks when combined with a supporting operating system.

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Advanced Intel Microprocessor Technologies

EM64T 64-bit extension CPUs with this technology have a new operating mode, called IA32E,

which has two sub-modes: Compatibility mode: Allows 64-bit operating systems to run 32-bit

and 16-bit software unmodified. The operating system can have 64-bit (in 64-bit mode), 32-bit and 16-bit (both on compatibility mode) programs running at the same time. However, 32-bit programs will run as if they were running on a 32-bit CPU, i.e. will access only up to 4 GB of RAM. The same idea goes to 16-bit program, that will still access only up to 1 MB of RAM.

64-bit mode: Allows 64-bit operation systems to use the new 64-bit addressing space provided by this technology.

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Advanced Intel Microprocessor Technologies

Enhanced SpeedStep technologies (power management) This technology provides power saving modes for the CPU which

consist of lowered CPU frequency and lowered CPU core voltage, so that overall power consumption of the processor is reduced and hence battery life extended.

Virtualization Technology (VT) this technology enables a CPU to act as if it were several CPUs

working in parallel, in order to enable several operating systems to run at the same time in the same machine (It must be supported by software e.g. VMWare).

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How to check CPU information

WCPUID softwarehttp://hp.vector.co.jp/authors/VA002374/src/download.html

Processor Type CPU Speed Socket/Slot Type Internal Clock L1, L2 cache Other (MMX, SSE)

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Intel Processor Numbering

Processor numbers are based on a variety of features that may include the processor's underlying architecture, cache, front side bus, clock speed, power and other Intel technologies that enhance your experience.

Architecture : Basic design of a microprocessor. May include technology and/or other architectural enhancements.

Cache: A temporary storage area for frequently accessed or recently accessed data. Having certain data stored in a cache speeds up the operation of the computer.

Front Side Bus: The connecting path between processor and other key components such as the memory controller hub. FSB speed is measured in GHz or MHz.

Clock Speed: Speed of the processor’s internal clock, which indicates how fast the processor can process data. Clock speed is usually measured in GHz.

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Processor numbers are categorized in 3-digit numerical sequences such as 800, 700, 600, 500, or 300. This number plus the processor family comprise the overall "processor name". Within each number sequence are specific processor numbers such as 840, 735, 640, 560, or 320. Processor numbers now represent a broader set of features that influence the overall user experience. Processor families may also change to reflect changes in Intel's product offerings.

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Intel's processor number system is used with the following brands

Intel® Core™2 Extreme processorIntel® Core™2 Quad processorIntel® Core™2 Duo processorIntel® Core™ Duo processorIntel® Core™2 Solo processorIntel® Core™ Solo processor

Intel® Pentium® processor Extreme EditionIntel® Pentium® D processorIntel® Pentium® dual-core processorIntel® Pentium® 4 processorIntel® Pentium® M processor²Mobile Intel® Pentium® 4 processorIntel® Celeron® D processorIntel® Celeron® M processorIntel® Celeron® processor

Intel® Xeon® processorIntel® Itanium® 2 processor

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