Types of Computers Super Computers Super Computers Mainframes Mainframes Mini Computers Mini Computers Micro Computers Micro Computers.

Types of ComputersTypes of Computers

Super ComputersSuper Computers MainframesMainframes Mini ComputersMini Computers Micro ComputersMicro Computers

The Computer SystemThe Computer System

HardwareHardware SoftwareSoftware UsersUsers Data Data

Communication Devices

Central Processing Unit

Output DevicesPrinters, Video Display

terminals, Plotters, Audio Output

Buses Primary Storage

Secondary Storage

Magnetic Disk, Optical disk, Magnetic Tape

Input devices

Keyboard, mouse, touch screen, source data automation

Hardware Components of A computer

ProcessingProcessing

Sequential ProcessingSequential Processing Reduced Instruction Set Computers (RISC)Reduced Instruction Set Computers (RISC)

FasterFaster Conventionally Complex Instruction Set Conventionally Complex Instruction Set

ComputingComputing Parallel ProcessingParallel Processing

Multiple CPUs – Break a problem into several Multiple CPUs – Break a problem into several smaller problems and work simultaneouslysmaller problems and work simultaneously

Massively Parallel Processing (MPP)Massively Parallel Processing (MPP) 100s or 1000s o chips to break problem into smaller 100s or 1000s o chips to break problem into smaller

processesprocesses

Moving Beyond…… Cluster ComputingMoving Beyond…… Cluster Computing

SEQUENTIAL SEQUENTIAL PROCESSINGPROCESSING

PARALLEL PROCESSINGPARALLEL PROCESSING

Program

CPUtask1

CPUtask2

CPUtask3

CPUtask4

CPUtask5

RESULT

Program

CPU

RESULT

Introduction To Personal Computing

The Processor The Processor

Looking Inside the Machine - The CPU

The procedure that transforms raw data into useful information is called processing. This function is divided between the computer's processor and memory.

The processor is also called the central processing unit (CPU). It manages all devices and performs the actual processing of data.

The CPU consists of one or more chips attached to the computer's main circuit board (the motherboard).

The Central Processing The Central Processing UnitUnit

Primary Memory

Input

Secondary Storage

Output

Communication Devices

registers

Control Unit ALU

Dual Core ProcessorsDual Core Processors A A dual coredual core processor is a processor is a CPUCPU with two separate cores, each with with two separate cores, each with

its own cache. It's the equivalent of getting two microprocessors in its own cache. It's the equivalent of getting two microprocessors in one.one.

In a single-core or traditional processor the CPU is fed In a single-core or traditional processor the CPU is fed instructions, it must order, execute, then selectively store in its instructions, it must order, execute, then selectively store in its cache for quick retrieval. When data outside the cache is required, cache for quick retrieval. When data outside the cache is required, it is retrieved through the system bus from it is retrieved through the system bus from random access memoryrandom access memory (RAM) or from storage devices. Accessing these slows down (RAM) or from storage devices. Accessing these slows down performance to the maximum speed the bus, RAM or storage performance to the maximum speed the bus, RAM or storage device will allow, which is far slower than the speed of the CPU. device will allow, which is far slower than the speed of the CPU. The situation is compounded when multi-tasking. In this case the The situation is compounded when multi-tasking. In this case the processor must switch back and forth between two or more sets of processor must switch back and forth between two or more sets of data streams and programs. CPU resources are depleted and data streams and programs. CPU resources are depleted and performance suffers.performance suffers.

In a dual core processor each core handles incoming data In a dual core processor each core handles incoming data simultaneously to improve efficiency. Just as two heads are better simultaneously to improve efficiency. Just as two heads are better than one, so are two hands. Now when one is executing the other than one, so are two hands. Now when one is executing the other can be accessing the system bus or executing its own code. Adding can be accessing the system bus or executing its own code. Adding to this favorable scenario, both AMD and Intel's dual-core flagships to this favorable scenario, both AMD and Intel's dual-core flagships are 64-bit.are 64-bit.

To utilize a dual core processor, the operating system must be able to To utilize a dual core processor, the operating system must be able to recognize the cores and the software must have simultaneous multi-recognize the cores and the software must have simultaneous multi-threading technology (SMT) written into its code. SMT enables threading technology (SMT) written into its code. SMT enables parallelparallel multi- multi-threading wherein the cores are served multi-threaded instructions in threading wherein the cores are served multi-threaded instructions in parallel. Without SMT the software will only recognize one core. Adobe parallel. Without SMT the software will only recognize one core. Adobe Photoshop is an example of SMT-aware software. SMT is also used with Photoshop is an example of SMT-aware software. SMT is also used with multi-processor systems common to servers. multi-processor systems common to servers.

A dual core processor is different from a multi-processor system. In the latter A dual core processor is different from a multi-processor system. In the latter there are two separate CPUs with their own resources. In the former, there are two separate CPUs with their own resources. In the former, resources are shared and the cores reside on the same chip. A multi-resources are shared and the cores reside on the same chip. A multi-processor system is faster than a system with a dual core processor, while a processor system is faster than a system with a dual core processor, while a dual core system is faster than a single-core system, all else being equal.dual core system is faster than a single-core system, all else being equal.

An attractive value of dual core processors is that they do not require a new An attractive value of dual core processors is that they do not require a new motherboard, but can be used in existing boards that feature the correct motherboard, but can be used in existing boards that feature the correct socket. For the average user the difference in performance will be most socket. For the average user the difference in performance will be most noticeable in multi-tasking until more software is SMT aware. Servers noticeable in multi-tasking until more software is SMT aware. Servers running multiple dual core processors will see an appreciable increase in running multiple dual core processors will see an appreciable increase in performance.performance.

Multi-coreMulti-core processors are the goal and as technology shrinks, there is more processors are the goal and as technology shrinks, there is more "real-estate" available on the die. In the fall of 2004 Bill Siu of Intel predicted "real-estate" available on the die. In the fall of 2004 Bill Siu of Intel predicted that current accommodating motherboards would be here to stay until 4-core that current accommodating motherboards would be here to stay until 4-core CPUs eventually force a changeover to incorporate a new memory controller CPUs eventually force a changeover to incorporate a new memory controller that will be required for handling 4 or more cores.that will be required for handling 4 or more cores.

. . Taking Advantage of Dual-core TechnologyTaking Advantage of Dual-core TechnologyA dual-core processor has many advantages especially for those looking to A dual-core processor has many advantages especially for those looking to boost their system's  multitasking computing power. Dual-core processors boost their system's  multitasking computing power. Dual-core processors provide two complete execution provide two complete execution corescores instead of one, each with an instead of one, each with an independent interface to the independent interface to the frontsidefrontside bus bus. Since each core has its own . Since each core has its own cache, the cache, the operating systemoperating system has sufficient resources to handle intensive has sufficient resources to handle intensive tasks in parallel, which provides a noticeable improvement to multitasking. tasks in parallel, which provides a noticeable improvement to multitasking. Complete optimization for the dual-core processor requires both the Complete optimization for the dual-core processor requires both the operating systemoperating system and and applicationsapplications running on the computer to support a running on the computer to support a technology called technology called tthread-hread-llevel evel pparallelism, or arallelism, or TLP. Thread-level parallelism TLP. Thread-level parallelism is the part of the OS or application that runs multiple is the part of the OS or application that runs multiple threadsthreads simultaneously, where threads refer to the part of a simultaneously, where threads refer to the part of a programprogram that can that can execute independently of other parts. execute independently of other parts. Key Terms To Understanding Dual-Key Terms To Understanding Dual-corecore dual-coredual-coreDual-core refers to a CPU that includes two complete execution cores Dual-core refers to a CPU that includes two complete execution cores per physical processor. per physical processor.

Even without a Even without a multithreadmultithread-enabled application, you will still see benefits of -enabled application, you will still see benefits of dual-core processors if you are running an OS that supports TLP. For dual-core processors if you are running an OS that supports TLP. For example, if you have example, if you have Microsoft Windows XPMicrosoft Windows XP (which supports (which supports multithreading), you could have your Internet browser open along with a multithreading), you could have your Internet browser open along with a virus scanner running in the background, while using Windows Media Player virus scanner running in the background, while using Windows Media Player to stream your favorite radio station and the dual-core processor will handle to stream your favorite radio station and the dual-core processor will handle the multiple threads of these programs running simultaneously with an the multiple threads of these programs running simultaneously with an increase in performance and efficiency. increase in performance and efficiency.

Today Windows XP and hundreds of applications already support multithread Today Windows XP and hundreds of applications already support multithread technology, especially applications that are used for editing and creating technology, especially applications that are used for editing and creating music filesmusic files, , videos and videos and graphicsgraphics because types of programs need to perform operations in parallel. because types of programs need to perform operations in parallel. As dual-core technology becomes more common in homes and the workplace, you can As dual-core technology becomes more common in homes and the workplace, you can expect to see more applications support thread-level parallelism. expect to see more applications support thread-level parallelism.

Intel & AMD Dual-core Desktop ProcessorsIntel & AMD Dual-core Desktop ProcessorsThe The Intel Pentium Processor Extreme Edition 840Intel Pentium Processor Extreme Edition 840 running at 3.2 GHz and Intel running at 3.2 GHz and Intel 955X Express Chipsets are being built into computers that are now entering the 955X Express Chipsets are being built into computers that are now entering the market. This is Intel's first desktop dual-core product supporting Hyper-Threading market. This is Intel's first desktop dual-core product supporting Hyper-Threading Technology. Processor features include the following: Technology. Processor features include the following:

Hyper-Threading Technology: Enables you to run multiple demanding applications at Hyper-Threading Technology: Enables you to run multiple demanding applications at the same time. the same time.

Intel Extended Memory 64 Technology: Provides flexibility for future applications that Intel Extended Memory 64 Technology: Provides flexibility for future applications that support both 32-bit and 64-bit computing. support both 32-bit and 64-bit computing.

Dual-Core: Two physical cores in one processor support better system responsiveness Dual-Core: Two physical cores in one processor support better system responsiveness and multi-tasking capability than a comparable single core processor.  and multi-tasking capability than a comparable single core processor.  [Source: Intel [Source: Intel Dual-core Desktop Processor]Dual-core Desktop Processor]

AMD also announced its line of desktop dual-core processors, the AMD also announced its line of desktop dual-core processors, the AMD Athlon 64 X2AMD Athlon 64 X2 processor family. The initial model numbers in the new family include the 4200+, processor family. The initial model numbers in the new family include the 4200+, 4400+, 4600+ and 4800+ (2.2GHz to 2.4GHz).The processors are based on AMD64 4400+, 4600+ and 4800+ (2.2GHz to 2.4GHz).The processors are based on AMD64 technology and are compatible with the existing base of x86 software, whether single-technology and are compatible with the existing base of x86 software, whether single-threaded or multithreaded. Software applications will be able to support AMD64 dual-threaded or multithreaded. Software applications will be able to support AMD64 dual-core processors with a simple BIOS upgrade and no substantial code changes. core processors with a simple BIOS upgrade and no substantial code changes. [Source: [Source: AMD Dual-core Desktop Processor]AMD Dual-core Desktop Processor]

Both companies have also announced or released dual-core processors for servers and Both companies have also announced or released dual-core processors for servers and workstations as well.workstations as well.

• Processing takes place in the PC's central processing unit (CPU).

• The system's memory also plays a crucial role in processing data.

• Both the CPU and memory are attached to the system's motherboard, which connects all the computer's devices together, enabling them to communicate.

How Computers Process Data – Where Processing Occurs

• RAM stores data and program code needed by the CPU. The contents of RAM change rapidly and often.

• Read-only memory (ROM) is nonvolatile (or permanent). It holds instructions that run the computer when the power is first turned on.

• The CPU accesses each location in memory by using a unique number, called the memory address.

How Computers Process Data –The Role of Memory

• The smallest usable unit of measure for memory is the byte – the amount of memory required to hold one character, like the letter A or the numeral 2.

• Computers work with larger chunks of data, measured in multiple bytes, as shown below:

Unit Approx. Value Actual Value (bytes) (bytes)

Kilobyte (KB) 1,000 1,024 Megabyte (MB) 1,000,000 1,048,576Gigabyte (GB) 1,000,000,000 1,073,741,824Terabyte (TB) 1,000,000,000,000 1,099,511,627,776

Looking Inside the Machine– How Memory is Measured

• Storage devices hold data not currently being used by the CPU. Data is commonly stored on a magnetic or optical disk. Each type uses a special medium for storing data on its surface.

• A disk drive is a device that reads data from and writes data to a disk. Most new computers feature a floppy disk drive, a hard disk drive, and an optical disk drive.

• The most common optical storage devices are CD-ROM and DVD-ROM drives.

Looking Inside the Machine - Storage Devices

• Registers

• RAM

• The System Clock

• The Bus

• Cache Memory

Factors Affecting Processing Speed

• The CPU contains a number of small memory areas, called registers, which store data and instructions while the CPU processes them.

• The size of the registers (also called word size) determines the amount of data with which the computer can work at a one time.

• Today, most PCs have 32-bit registers, mean the CPU can process four bytes of data at one time. Register sizes are rapidly growing to 64 bits.

Factors Affecting Processing Speed – Registers

• The amount of RAM in a PC has a direct affect on the system's speed.

• The more RAM a PC has, the more program instructions and data can be held in memory, which is faster than storage on disk.

• If a PC does not have enough memory to run a program, it must move data between RAM and the hard disk frequently. This process, called swapping, can greatly slow a PC's performance.

Factors Affecting Processing Speed – RAM

More RAM = Better Performance!

• The computer's system clock sets the pace for the CPU by using a vibrating quartz crystal.

• A single "tick" of the clock is the time required to turn a transistor off and back on. This is called a clock cycle.

• Clock cycles are measured in Hertz (Hz), a measure of cycles per second. If a computer has a clock speed of 300 MHz, then its system clock "ticks" 300 million times every second.

• The faster a PC's clock runs, the more instructions the PC can execute each second.

Factors Affecting Processing Speed –The System Clock

• A bus is a path between the components of a computer. Data and instructions travel along these paths.

• The data bus' width determines how many bits can be transmitted between the CPU and other devices.

• The address bus runs only between the CPU and

RAM, and carries nothing but memory addresses for the CPU to use.

• Peripheral devices are connected to the CPU by an expansion bus.

Factors Affecting Processing Speed –The Bus

• Cache memory is high-speed memory that holds the most recent data and instructions that have been loaded by the CPU.

• Cache is located directly on the CPU or between the CPU and RAM, making it faster than normal RAM.

• CPU-resident cache is called Level-1 (L1) cache. External cache is called Level-2 (L2) cache.

• The amount of cache memory has a tremendous impact on the computer's speed.

Factors Affecting Processing Speed –Cache Memory

• Ports

• Expansion Slots and Boards

Extending the Processor's Powerto Other Devices

• External devices—such as those used for input and output—are connected to the system by ports on the back of the computer.

• PCs feature a number of built-in ports, which are ready to accept devices such as a printer, mouse, keyboard, phone line, microphone and speakers, and others.

• Most computers come with a serial port and a parallel port. A serial port transmits one bit of data at a time; a parallel port transmits data one byte at a time.

Extending the Processor's Powerto Other Devices – Ports

• If the PC does not have a port for an external device, you can install an expansion board into one of the empty expansion slots.

• A board provides the correct port for the new device, and connects the device to the CPU by way of the computer's expansion bus.

• Newer bus technologies such as Universal Serial Bus (USB) and IEEE 1394(Firewire) enable many devices to be connected to one port.

• Small Computer System Interface (SCSI) is an older standard for extending the bus to multiple devices through a single port.

Adding Other Devices – Expansion Slots and Boards