MIS- InformationTechnology Concepts

Filmon Habtemichael

Why Learn About Hardware?

• Organizations invest in computer hardware to improve– worker productivity, – Increase revenue, – reduce costs, – provide better customer service,– speed up time-to-market, and– enable collaboration among employees.

• Organizations that don’t make wise hardware investments will be stuck with outdated equipment that is unreliable and cannot take advantage of the latest software advances.

• Such obsolete hardware can place an organization at a competitive disadvantage.

Hardware

• Any machinery (most of which uses digital circuits) that assists in the input, processing, storage, and output activities of an information system.

COMPUTER SYSTEMS: INTEGRATING THE POWEROF TECHNOLOGY

• As auto manufacturers must match the intended use of a vehicle to its components, so too must business managers select the hardware components of an effective information system.

• E.g The Iowa Health System– Store and manage image data such as magnetic

resonance images (MRIs).– NHS failure

Central Processing Unit (CPU)

• It is also called microprocessor or processor• The part of the computer that consists of three associated elements: the

arithmetic/logic unit, the control unit, and the register areas.Arithmetic/logic unit (ALU)

• Performs mathematical calculations and makes logical comparisons.Control unit

• Sequentially accesses program instructions, decodes them, and coordinates the flow of data in and out of the ALU, registers, primary storage, and even secondary storage and various output devices.Register

• A high-speed storage area in the CPU used to temporarily hold small units of program instructions and data immediately before, during, and after execution by the CPU.

• Registers provide temporary memory storage locations within the processor.

• Three kinds of buses link the CPU, primary storage, and the other devices in the computer system.

• The data bus moves data to and from primary storage. • The address bus transmits signals for locating a given

address in primary storage, indicating where data should be placed.

• The control bus transmits signals specifying whether to read or write data to or from a given primary storage address, input device, or output device.

CPU speed

• The speed and performance of a computer’s microprocessors help determine a computer’s processing power.

• The first factor is Word length: the number of bits that the computer can process at one time.– 32 bit-process 4 bytes– 64 bit process 8 bytes data at the same time

• A second factor affecting chip speed is cycle speed– measured in megahertz

• A third factor affecting speed is the data bus width.– For better performance the word length and data

bus width should match

Memory

Random access memory (RAM)– A form of memory in which instructions or data

can be temporarily stored.Read-only memory (ROM)– A nonvolatile form of memory.

Cache memory– A type of high-speed memory that a processor can

access more rapidly than main memory.

Secondary Storage Technology

Magnetic Disk• The most widely used secondary-storage

medium today is magnetic disk. There are two kinds of magnetic disks: – floppy disks (used in PCs) and – hard disks (used on large commercial disk drives

and PCS

Magnetic Tape

• is a type of sequential secondary storage medium, now used primarily for storing backups.

• Cheaper and slower in retrieval• U.S. federal government is the largest user of

magnetic tape in the world, buying over 1 million reels of tape each year

DVD

• DVD-5 (DVD-R, DVD-RW, and DVD+RW)– single sided single layered– is capable of holding up to 4.37 GB worth of data

and is available in each of the media formats listed in the above heading.

• DVD-9 (DVD+R9 or DVD+R DL (Dual Layered))– singled sided dual layered– DVD-9 is capable of holding up to 8.5 GB worth of

data

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• DVD-10 (DVD-R, DVD-RW, and DVD+RW)– double sided single layered– is capable of holding up to 9.4 GB worth of data and is

available in each of the media formats listed in the above heading.

– It is important to understand when buying these discs they are labeled as "DVD-RW Only" or "DVD+RW Only", make sure to purchase the discs designed for your drive.

• DVD-18 (DVD+R9 or DVD+R DL (Dual Layered))– double sided dual layered, – is capable of holding up to 15.9 GB worth of data

DVD standards

• Unfortunately, unlike recordable CD drives, there are many different competing standards for creating DVD discs

• DVD-R And DVD-RW arean approved standard by DVD Forum

• DVD+R And DVD+RW are DVD+RW Alliance standard of disc.

Blu Ray

• The Blu-ray high-definition video-disc format based on blue-laser technology stores at least three times as much data as a DVD now holds.

• The primary use for this new format is in home entertainment equipment to store high-definition video, though this format can also store computer data.

Holographic versatile disc

• Holographic versatile disc (HVD) is a holographic storage format that looks like a DVD but is capable of storing far more data.

• Prototype HVD devices have been created with a capacity of 3.9 terabytes (TB) and a transfer rate of 1 gigabit per second (1 Gbps). At that capacity, an HVD could store as much information as 830 DVDs or 160 Blu-Ray discs.

Access Method

• Sequential access A retrieval method in which data must be accessed in the order in which it is stored.

• Direct access A retrieval method in which data can be retrieved without the need to read and discard other data.

• sequential access storage devices (SASDs) A device used to sequentially access secondary storage data.

• direct access storage devices (DASDs). A device used for direct access of secondary storage data.

Redundant array of independentdisks (RAID)

• A method of storing data that generates extra bits of data from existing data, allowing the system to create a “reconstruction map” so that if a hard drive fails, it can rebuild lost data.

• With this approach, data is split and stored on different physical disk drives using a technique called striping to evenly distribute the data.

Disk mirroring• A process of storing data that provides an exact copy that

protects users fully in the event of data loss.• One application of RAID

Enterprise Storage Options

• Attached Storage• Network-Attached Storage– Storage devices that attach to a network instead of to

a single computer.– NAS includes software to manage storage access and

file management and relieve the users’ computers of those tasks

– both application software and files can be served faster because they are not competing for the same processor resources

• Storage Area Network– a special-purpose, high-speed network that

provides direct connections between data-storage devices and computers across the enterprise

– Using a SAN, an organization can centralize the people, policies, procedures, and practices

Computing

• Parallel computing is the simultaneous execution of the same task on multiple processors to obtain results faster.

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• Grid computing is the use of a collection of computers, often owned by multiple individuals or organizations, to work in a coordinated manner to solve a common problem.

• Grid computing is a low-cost approach to parallel computing.

• European and Asian researchers are using a grid consisting of some 40,000 computers spread across 45 countries to combat the deadly bird flu.

Examples of grid computing• SETI (Search for Extraterrestrial Intelligence) @Home project

– SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI).

– You can participate by running a free program that downloads and analyzes radio telescope data.

• BOINC (Berkeley Open Infrastructure for Network Computing)– Developed by University of California, Berkeley, BOINC lets you

contribute computing power on your home PC to projects doing research in many scientific areas.

– BOINC is a common one for academic projects seeking public volunteers• Folding@home (abbreviated as FAH or F@h)

– Understanding how proteins self-assemble (“protein folding”) is a holy grail of modern molecular biophysics.

cont• Einstein@Home

Einstein@Home is a program that uses your computer’s idle time to search for spinning neutron stars (also called pulsars) using data from the LIGO gravitational wave detector. It also searches for radio pulsars in binary systems, using data from the Arecibo Observatory in Puerto Rico.

• LHC@home LHC@home is a volunteer computing program which enables you to contribute idle time on your computer to help physicists develop and exploit particle accelerators, such as CERN’s Large Hadron Collider.

• Cloud computing involves using a giant cluster of computers that serves as a host to run applications that require high-performance computing.

• Cloud computing supports a wider variety of applications than grid computing and pools computing resources so they can be managed primarily by software rather than people.

Cloud computing

Grid computing Cloud computingWhat? Grids enable access to shared computing

power and storage capacity from your desktop

Clouds enable access to leased computing power and storage capacity from your desktop

Who provides the service? Research institutes and universities federate their services around the world through projects such as EGI-InSPIRE and the European Grid Infrastructure.

Large individual companies e.g. Amazon and Microsoft and at a smaller scale, institutes and organisations deploying open source software such as Open Slate, Eucalyptus and Open Nebula.

Who uses the service? Research collaborations, called "Virtual Organisations", which bring together researchers around the world working in the same field.

Small to medium commercial businesses or researchers with generic IT needs

Who pays for the service? Governments - providers and users are usually publicly funded research organisations, for example through National Grid Initiatives.

The cloud provider pays for the computing resources; the user pays to use them

Where are the computing resources? In computing centres distributed across different sites, countries and continents.

The cloud providers private data centres which are often centralised in a few locations with excellent network connections and cheap electrical power.

Why use them? - You don`t need to buy or maintain your own large computer centre - You can complete more work more quickly and tackle more difficult problems. - You can share data with your distributed team in a secure way.

- You don`t need to buy or maintain your own personal computer centre - You can quickly access extra resources during peak work periods

What are they useful for? Grids were designed to handle large sets of limited duration jobs that produce or use large quantities of data (e.g. the LHC and life sciences)

Clouds best support long term services and longer running jobs (E.g. facebook.com)

How do they work? Grids are an open source technology. Resource users and providers alike can understand and contribute to the management of their grid

Clouds are a proprietary technology. Only the resource provider knows exactly how their cloud manages data, job queues, security requirements and so on.

Benefits? - Collaboration: grid offers a federated platform for distributed and collective work.- Ownership : resource providers maintain ownership of the resources they contribute to the grid- Transparency: the technologies used are open source, encouraging trust and transparency.- Resilience: grids are located at multiple sites, reducing the risk in case of a failure at one site that removes significant resources from the infrastructure.

- Flexibility: users can quickly outsource peaks of activity without long term commitment- Reliability: provider has financial incentive to guarantee service availability (Amazon, for example, can provide user rebates if availability drops below 99.9%)- Ease of use: relatively quick and easy for non-expert users to get started but setting up sophisticated virtual machines to support complex applications is more difficult.

Drawbacks? - Reliability: grids rely on distributed services maintained by distributed staff, often resulting in inconsistency in reliability across individual sites, although the service itself is always available.- Complexity: grids are complicated to build and use, and currently users require some level of expertise.- Commercial: grids are generally only available for not-for-profit work, and for proof of concept in the commercial sphere

- Generality: clouds do not offer many of the specific high-level services currently provided by grid technology.- Security: users with sensitive data may be reluctant to entrust it to external providers or to providers outside their borders.- Opacity: the technologies used to guarantee reliability and safety of cloud operations are not made public.- Rigidity: the cloud is generally located at a single site, which increases risk of complete cloud failure.- Provider lock-in: there’s a risk of being locked in to services provided by a very small group of suppliers.

When? The concept of grids was proposed in 1995. The Open science grid (OSG) started in 1995 The EDG (European Data Grid) project began in 2001.

In the late 1990`s Oracle and EMC offered early private cloud solutions . However the term cloud computing didn't gain prominence until 2007.

Advanced input

• A magnetic stripe card– stores limited amounts of data by modifying the

magnetism of tiny iron-based particles contained in a band on the card.

– Magnetic stripe cards are commonly used in credit cards, transportation tickets, and driver’s licenses.

– the card contain any information about the cardholder in the magnetic stripe.

• Point-of-Sale Devices– are terminals used in retail operations to enter

sales information into the computer system. The POS device then computes the total charges, including tax.

Automated Teller Machine (ATM) Devices• Another type of special-purpose input/output device, the

automated teller machine (ATM)• is a terminal that bank customers use to perform withdrawals

and other transactions with their bank accounts. • The ATM, however, is no longer used only for cash and bank

receipts. – Companies use various ATM devices, sometimes called kiosks, to

support their business processes.– Some can dispense tickets, such as for airlines, concerts, and soccer

games. – Some colleges use them to produce transcripts.

Pen Input Devices• By touching the screen with a pen input

device, you can activate a command or cause the computer to perform a task, enter handwritten notes, and draw objects and figures.

Touch-Sensitive Screens• Advances in screen technology allow display

screens to function as input as well as output devices

• E.g windows 8 pcs

Bar-Code Scanners• A bar-code scanner employs a laser scanner to read a

bar-coded label widely used in grocery store checkouts and warehouse inventory control.

• A radio frequency signal can update this memory as the status of the item changes. The data transmitted by the tag might provide identification, location information, or details about the product tagged, such as date manufactured, retail price, color, or date of purchase.

Advanced Output Devices

• Eyebud Screens• Eyebud screens are portable media devices

that display video in front of one eye. • They employ optical technology that provides

very high resolution and “enlarges” the video or images.

Categories of Computers

• A personal computer (PC), which is sometimes referred to as a microcomputer, is one that can be placed on a desktop or carried from room to room

• A workstation also fits on a desktop but has more powerful mathematical and graphics processing capability than a PC and can perform more complicated tasks than a PC in the same amount of time. Workstations are used for scientific, engineering, and design work that requires powerful graphics or computational capabilities.

Thin Client• A thin client is a low-cost, centrally managed

computer with no extra drives, such as a CD or DVD drive, or expansion slots.

• A mainframe is the largest computer, a powerhouse with massive memory and extremely rapid processing power. It is used for very large business, scientific, or military applications where a computer must handle massive amounts of data or many complicated processes.

• A supercomputer is a highly sophisticated and powerful computer that is used for tasks requiring extremely rapid and complex calculations with hundreds of thousands of variable factors.

• Supercomputers use parallel processing and can perform billions and even trillions of calculations per second, many times faster than the largest mainframe.

• Server computer specifically optimized to provide software and other resources to other computers over a network.

Capacity Planning and Scalability• Capacity planning is the process of predicting when a

computer hardware system becomes saturated.• It considers factors such as the

– maximum number of users that the system can accommodate,

– the impact of existing and future software applications, and – performance measures such as minimum response time for

processing business transactions. • Although capacity planning is performed by information

system specialists, input from managers is essential.

• Scalability refers to the ability of a computer, product, or system to expand to serve a larger number of users without breaking down.

• There are several approaches to achieving scalability.– One is to scale up, replacing, for example, a small server with a

larger multiprocessor server or even a mainframe. – Another approach is to scale out, which involves adding a large

number of smaller servers. • The choice of approach depends on the nature of the

application or set of applications requiring upgraded hardware capacity.

Hardware Acquisition and the Total Cost of Ownership (TCO) of Technology Assets• The actual cost of owning technology

resources includes both direct and indirect costs,

• TCO designates the total cost of owning technology resources, including initial purchase costs, the cost of hardware and software upgrades, maintenance, technical support, and training.

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• A key to reducing TCO is to create a comprehensive asset management plan.

• Software tools are now available to help identify and track these technology assets.

• TCO for a PC might run up to three times the original purchase price

• Some of these tools even show managers what assets are breaking down and why, and when these assets should be cycled out of service.

Monitoring Technology Trends

• Computing technology continues to change at a blinding pace, requiring managers to constantly monitor technology trends and make decisions about upgrading the organization’s information technology infrastructure.

• New hardware technologies can provide new ways of organizing work and sources of new products and services.