DOCSLIB.ORG

Computing Hardware 5/5: Secondary Storage Section Objectives

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Computing Hardware 5/5: Secondary Storage Section Objectives Unit A451: Computer systems and programming Section 2: Computing Hardware 5/5: Secondary Storage Section Objectives Candidates should be able to: (a) explain the need for secondary storage (b) describe common storage technologies such as optical, magnetic and solid state (c) Discuss the advantages and disadvantages of different types of secondary storage The need for secondary storage •We all want to store files over a long period of time. We keep photographs, projects, music, films, letters and spreadsheets on our computers. We also expect our programs to be there when we switch the computer on. (s) explain the need for secondary storage The need for secondary storage This long term storage is sometimes called Secondary Storage / Memory (primary memory is the main memory) (s) explain the need for secondary storage The need for secondary storage Although RAM can store the data and programs used when a computer system is actually running, it is volatile, meaning it loses its contents without a power source. (s) explain the need for secondary storage The need for secondary storage Secondary storage therefore needed because it is non-volatile, meaning it retains its contents without the need for a power supply. It also has the large storage capacity needed to store the operating system and all the programs and files needed by a modern computer system. Because we need a lot of it, it therefore needs to be cheap. (s) explain the need for secondary storage Magnetic Storage This is the oldest of the technologies and is used in floppy disks, hard disks and tapes. Magnetic disks are read with a moving head inside the disk drive and magnetic tapes are read by moving the tape past a read-write head. •Advantages High Capacity Cheap relative to amount of space •Disadvantages Non Portable, Slow write speed to tape Can be damaged by magnets and wiped easily (t) describe common storage technologies such as optical, magnetic and solid state Optical Storage •The word “optical” should make you think about the eye and how we see the world in terms of reflected light. Optical media work in a similar way. They use a surface where a pattern of reflective and non-reflective areas represents the binary data. •Advantages CD drives are common in PC’s and Laptops Easily portable Blu-ray discs are easily layered so can hold massive amount of data •Disadvantages Easily damaged/scratched Quite expensive for re-writable discs (t) describe common storage technologies such as optical, magnetic and solid state Solid State (Flash) Storage Solid state devices are a form of flash memory, it is therefore non- volatile like ROM so the contents are not lost when there is no power supply, but able to be written to as in RAM. Solid State Devices can replace the hard drive as the main secondary storage device in a computer, where really large storage capacities are not required. •Advantages Fast read and write times compared to both other types Resistant to shock so highly portable •Disadvantages Low storage compared to other two types Expensive for high capacity storage (t) describe common storage technologies such as optical, magnetic and solid state Storage Considerations Capacity: The amount of data to be stored / size of the file. Are you a school pupil wanting to store an essay, or a multinational company with years worth of records? Speed: How quickly the user needs to be able to access the data from the storage device? Portability: Whether the data needs to be moved from one place to another such as from home to school. Some companies store back-ups of important data ‘off-site’. Durability: How long the storage media can reasonably be expected to last? Remember that a lot of secondary storage needs to be portable. Reliability: Whether the data can always be accessed reliably and in the format in which it was saved. (u) select suitable storage for a given application and justify choice using characteristics such as capacity, speed, portability, durability and reliability. Your Tasks Task 1 Explain the need for secondary storage in computer systems (4 marks) Task 2 Discuss the advantages and disadvantages of each storage device. For higher marks, compare them to each other. (6 marks) (u) select suitable storage for a given application and justify choice using characteristics such as capacity, speed, portability, durability and reliability. .
Load more

Recommended publications
  • Fast Non-Volatile RAM Products Superior Price and Performance from a Source You Can Trust
    Fast Non-Volatile RAM Products Superior price and performance from a source you can trust www.freescale.com/MRAM The Future of Non-Volatile Read/Write Memory is Magnetic Freescale Semiconductor delivers the world’s non-volatile for greater than 20 years. Commercial MRAM Products Selector Guide Freescale MRAM Features first commercial magnetoresistive random SRAM-compatible packaging assures Part Number Density Configuration Voltage Speed Grades Temperature Package RoHS Compliant • 35 ns read/write cycle time access memory (MRAM) products. Our alternate sourcing from other suppliers. MR2A16ATS35C 4 Mb 256 Kb x 16 3.3V 35 ns 0 to 70°C 44-TSOP Type II √ • Unlimited read/write endurance MRAM products store data using magnetic MR1A16AYS35 2 Mb 128 Kb x 16 3.3V 35 ns 0 to 70°C 44-TSOP Type II √ • 3.3V ± 10 percent power supply polarization rather than electric charge. Extended Temperature Range and MR0A16AYS35 1 Mb 64 Kb x 16 3.3V 35 ns 0 to 70°C 44-TSOP Type II √ • Always non-volatile with greater than MRAM stores data for decades while reading Superior Reliability 20-year retention and writing at SRAM speed without wear- MRAM delivers a 3 volt high-density out. MRAM products use small, simple • Magnetically shielded to greater than non-volatile RAM that operates over extended cells to deliver the highest density and best 25 oersted (Oe) temperature. MRAM does not exhibit the price/performance in the non-volatile RAM • Commercial, Industrial and Extended charge storage failure modes that limit the marketplace. With our new expanded product Temperature Options data retention or endurance of line, we serve a growing portion of the other technologies.
    [Show full text]
  • Magnetic Storage- Magnetic-Core Memory, Magnetic Tape,RAM
    Magnetic storage- From magnetic tape to HDD Juhász Levente 2016.02.24 Table of contents 1. Introduction 2. Magnetic tape 3. Magnetic-core memory 4. Bubble memory 5. Hard disk drive 6. Applications, future prospects 7. References 1. Magnetic storage - introduction Magnetic storage: Recording & storage of data on a magnetised medium A form of „non-volatile” memory Data accessed using read/write heads Widely used for computer data storage, audio and video applications, magnetic stripe cards etc. 1. Magnetic storage - introduction 2. Magnetic tape 1928 Germany: Magnetic tape for audio recording by Fritz Pfleumer • Fe2O3 coating on paper stripes, further developed by AEG & BASF 1951: UNIVAC- first use of magnetic tape for data storage • 12,7 mm Ni-plated brass-phosphorus alloy tape • 128 characters /inch data density • 7000 ch. /s writing speed 2. Magnetic tape 2. Magnetic tape 1950s: IBM : patented magnetic tape technology • 12,7 mm wide magnetic tape on a 26,7 cm reel • 370-730 m long tapes 1980: 1100 m PET –based tape • 18 cm reel for developers • 7, 9 stripe tapes (8 bit + parity) • Capacity up to 140 MB DEC –tapes for personal use 2. Magnetic tape 2014: Sony & IBM recorded 148 Gbit /squareinch tape capacity 185 TB! 2. Magnetic tape Remanent structural change in a magnetic medium Analog or digital recording (binary storage) Longitudinal or perpendicular recording Ni-Fe –alloy core in tape head 2. Magnetic tape Hysteresis in magnetic recording 40-150 kHz bias signal applied to the tape to remove its „magnetic history” and „stir” the magnetization Each recorded signal will encounter the same magnetic condition Current in tape head proportional to the signal to be recorded 2.
    [Show full text]
  • Archiving Online Data to Optical Disk
    ARCHIVING ONLINE DATA TO OPTICAL DISK By J. L. Porter, J. L. Kiesler, and D. A. Stedfast U.S. GEOLOGICAL SURVEY Open-File Report 90-575 Reston, Virginia 1990 U.S. DEPARTMENT OF THE INTERIOR MANUEL LUJAN, JR., Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information Copies of this report can be write to: purchased from: Chief, Distributed Information System U.S. Geological Survey U.S. Geological Survey Books and Open-File Reports Section Mail Stop 445 Federal Center, Bldg. 810 12201 Sunrise Valley Drive Box 25425 Reston, Virginia 22092 Denver, Colorado 80225 CONTENTS Page Abstract ............................................................. 1 Introduction ......................................................... 2 Types of optical storage ............................................... 2 Storage media costs and alternative media used for data archival. ......... 3 Comparisons of storage media ......................................... 3 Magnetic compared to optical media ............................... 3 Compact disk read-only memory compared to write-once/read many media ................................... 6 Erasable compared to write-once/read many media ................. 7 Paper and microfiche compared to optical media .................... 8 Advantages of write-once/read-many optical storage ..................... 8 Archival procedure and results ........................................ 9 Summary ........................................................... 13 References ..........................................................
    [Show full text]
  • Computer Files & Data Storage
    STORAGE & FILE CONCEPTS, UTILITIES (Pages 6, 150-158 - Discovering Computers & Microsoft Office 2010) I. Computer files – data, information or instructions residing on secondary storage are stored in the form of a file. A. Software files are also called program files. Program files (instructions) are created by a computer programmer and generally cannot be modified by a user. It’s important that we not move or delete program files because your computer requires them to perform operations. Program files are also referred to as “executables”. 1. You can identify a program file by its extension:“.EXE”, “.COM”, “.BAT”, “.DLL”, “.SYS”, or “.INI” (there are others) or a distinct program icon. B. Data files - when you select a “save” option while using an application program, you are in essence creating a data file. Users create data files. 1. File naming conventions refer to the guidelines followed while assigning file names and will vary with the operating system and application in use (see figure 4-1). File names in Windows 7 may be up to 255 characters, you're not allowed to use reserved characters or certain reserved words. File extensions are used to identify the application that was used to create the file and format data in a manner recognized by the source application used to create it. FALL 2012 1 II. Selecting secondary storage media A. There are three type of technologies for storage devices: magnetic, optical, & solid state, there are advantages & disadvantages between them. When selecting a secondary storage device, certain factors should be considered: 1. Capacity - the capacity of computer storage is expressed in bytes.
    [Show full text]
  • Qt2t0089x7 Nosplash Af5b9567
    UNIVERSITY OF CALIFORNIA Los Angeles Interface Engineering of Voltage-Controlled Embedded Magnetic Random Access Memory A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Electrical and Computer Engineering by Xiang Li 2018 © Copyright by Xiang Li 2018 ABSTRACT OF THE DISSERTATION Interface Engineering of Voltage-Controlled Embedded Magnetic Random Access Memory by Xiang Li Doctor of Philosophy in Electrical and Computer Engineering University of California, Los Angeles, 2018 Professor Kang Lung Wang, Chair Magnetic memory that utilizes spin to store information has become one of the most promising candidates for next-generation non-volatile memory. Electric-field-assisted writing of magnetic tunnel junctions (MTJs) that exploits the voltage-controlled magnetic anisotropy (VCMA) effect offers great potential for high density and low power memory applications. This emerging Magnetoelectric Random Access Memory (MeRAM) based on the VCMA effect has been investigated due to its lower switching current, compared with traditional current-controlled devices utilizing spin transfer torque (STT) or spin-orbit torque (SOT) for magnetization switching. It is of great promise to integrate MeRAM into the advanced CMOS back-end-of-line (BEOL) processes for on-chip embedded applications, and enable non-volatile electronic systems with low static power dissipation and instant-on operation capability. To achieve the full potential of MeRAM, it is critical to design magnetic materials with high voltage-induced ii writing efficiency, i.e. VCMA coefficient, to allow for low write energy, low write error rate, and high density MeRAM at advanced nodes. In this dissertation, we will first discuss the advantage of MeRAM over other memory technologies with a focus on array-level memory performance, system-level 3D integration, and scaling at advanced nodes.
    [Show full text]
  • The Effects of Magnetic Fields on Magnetic Storage Media Used in Computers
    NITED STATES ARTMENT OF MMERCE NBS TECHNICAL NOTE 735 BLICATION of Magnetic Fields on Magnetic Storage Media Used in Computers — NATIONAL BUREAU OF STANDARDS The National Bureau of Standards^ was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measure- ment system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, the Center for Computer Sciences and Technology, and the Office for Information Programs. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scien- tific community, industry, and commerce. The Institute consists of a Center for Radia- tion Research, an Office of Measurement Services and the following divisions: Applied Mathematics—Electricity—Heat—Mechanics—Optical Physics—Linac Radiation^—Nuclear Radiation^—Applied Radiation-—Quantum Electronics' Electromagnetics^—Time and Frequency'—Laboratory Astrophysics'—Cryo- genics'. THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research lead- ing to improved methods of measurement, standards, and data on the properties of well-characterized materials needed by industry, commerce, educational institutions, and Government; provides advisory and research services to other Government agencies; and develops, produces, and distributes standard reference materials.
    [Show full text]
  • Design and Test of Embedded Srams Andrei S. Pavlov
    Design and Test of Embedded SRAMs by Andrei S. Pavlov A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Electrical and Computer Engineering Waterloo, Ontario, Canada, 2005 c Andrei S. Pavlov 2005 I hereby declare that I am the sole author of this thesis. I authorize the University of Waterloo to lend this thesis to other institutions or individuals for the purpose of scholarly research. Andrei S. Pavlov I further authorize the University of Waterloo to reproduce this thesis by photocopying or other means, in total or in part, at the request of other institutions or individuals for the purpose of scholarly research. Andrei S. Pavlov ii Abstract Embedded SRAMs can occupy the majority of the chip area in SoCs. The increased process spreads of modern scaled-down technologies and non-catastrophic defect-related sensitivity to environmental parameters can compromise the stability of SRAM cells, which is quantified by a low Static Noise Margin (SNM). A Stability Fault (SF) can present itself in a cell whose SNM is so small that it can accidentally flip in the worst-case operating conditions. In this work, we conduct a comprehensive SRAM SNM sensitivity analysis and identify the major factors causing low SNM. Based on this study, we propose a Weak Cell Fault Model, which can be used in fault simulations to mimic an SRAM cell with a compromised SNM. Furthermore, we have derived an analytical expression for the SNM of the recently proposed loadless 4T SRAM cell. Reading a 6T SRAM cell with bit lines precharged to VDD may not detect several types of defects in the pull-up path of the cell.
    [Show full text]
  • Memory and Storage Systems
    CHAPTER 3 MEMORY AND STORAGE SYSTEMS Chapter Outline Chapter Objectives 3.1 Introduction In this chapter, we will learn: 3.2 Memory Representation ∑ The concept of memory and its 3.3 Random Access Memory representation. 3.3.1 Static RAM ∑ How data is stored in Random Access 3.3.2 Dynamic RAM Memory (RAM) and the various types of 3.4 Read Only Memory RAM. 3.4.1 Programmable ROM ∑ How data is stored in Read Only Memory 3.4.2 Erasable PROM (ROM) and the various types of ROM. 3.4.3 Electrically Erasable PROM ∑ The concept of storage systems and the 3.4.4 Flash ROM various types of storage systems. 3.5 Storage Systems ∑ The criteria for evaluating storage 3.6 Magnetic Storage Systems systems. 3.6.1 Magnetic Tapes 3.6.2 Magnetic Disks 3.7 Optical Storage Systems 3.1 INTRODUCTION 3.7.1 Read only Optical Disks 3.7.2 Write Once, Read Many Disks Computers are used not only for processing of data 3.8 Magneto Optical Systems for immediate use, but also for storing of large 3.8.1 Principle used in Recording Data volume of data for future use. In order to meet 3.8.2 Architecture of Magneto Optical Disks these two specifi c requirements, computers use two 3.9 Solid-State Storage Devices types of storage locations—one, for storing the data 3.9.1 Structure of SSD that are being currently handled by the CPU and the 3.9.2 Advantages of SSD other, for storing the results and the data for future 3.9.3 Disadvantages of SSD use.
    [Show full text]
  • Storage Media
    Storage media This is a sample chapter from the forthcoming book, Files that Last, by Gary McGath. Copyright 2012 by Gary McGath, all rights reserved. Say see you later to your data And sing an ode to dead code. Any drive can make you hate her When a backup is owed. Bill Roper, “Hard Drive Calypso” Files are no more durable than the media they are stored on. What’s the best alternative if you’re concerned with longevity: tape, hard drive, flash, DVD, or something else? There isn’t a clear answer, since each one has its own strengths and weaknesses, but some are better than others, and you can get good material or cheap junk in any medium. Whatever you choose, care and storage can make a big difference to its lifespan. Sometimes you’re on the receiving end of legacy files, and you have to deal with the medium they’re on. In addition to current and upcoming media, this chapter looks at some of the older formats and their issues. Compact discs Compact discs (CDs) and their high-density relatives, digital video discs (DVDs) and Blu-Ray, are often a good choice for archiving. (These are always “discs,” not “disks.”) They’re optical storage media, written and read by lasers. They’re strictly passive objects, with no moving parts to fail, and they aren’t susceptible to magnetic fields, so they can last quite a while. They’ve been common for a long time now, so it should be fairly easy to get drives for them for the next couple of decades.
    [Show full text]
  • Preservation Management of Digital Materials: the Handbook
    Preservation Management of Digital Materials: The Handbook www.dpconline.org/graphics/handbook/ 5. Media and Formats 5. Outline Intended primary audience Operational managers and staff in repositories, publishers and other data creators, third party service providers. Assumed level of knowledge of digital preservation Novice to Intermediate. Purpose To outline the range of options available when creating digital materials and some of the major implications of selection.To point to more detailed sources of advice and guidance.To indicate areas where it is necessary to maintain an active technology watch. 5.1 Media It is important to have an understanding of the various media for storage because they require different software and hardware equipment for access, and have different storage conditions and preservation requirements.They also have varying suitability according to the storage capacity required, and preservation or access needed. Although it is very easy to focus on the traditional conservation of the physical artefact, it is important to recognise that most electronic media will be threatened by obsolescence of the hardware and software to access them.This often occurs long before deterioration of media (which have been subject to appropriate storage and handling) becomes a problem. However, appropriate selection, storage and handling of media is still essential to any preservation strategy (see Storage and Preservation). Obsolescence of previous storage media has occurred in rapid succession. In floppy disks alone we have seen a progression from 8 in to 5.25 in and then 3.5 in formats, with each change leading to rapid discontinuation of previous formats and difficulty in obtaining or maintaining access devices for them.
    [Show full text]
  • A Study About Non-Volatile Memories
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 29 July 2016 doi:10.20944/preprints201607.0093.v1 1 Article 2 A Study about Non‐Volatile Memories 3 Dileep Kumar* 4 Department of Information Media, The University of Suwon, Hwaseong‐Si South Korea ; [email protected] 5 * Correspondence: [email protected] ; Tel.: +82‐31‐229‐8212 6 7 8 Abstract: This paper presents an upcoming nonvolatile memories (NVM) overview. Non‐volatile 9 memory devices are electrically programmable and erasable to store charge in a location within the 10 device and to retain that charge when voltage supply from the device is disconnected. The 11 non‐volatile memory is typically a semiconductor memory comprising thousands of individual 12 transistors configured on a substrate to form a matrix of rows and columns of memory cells. 13 Non‐volatile memories are used in digital computing devices for the storage of data. In this paper 14 we have given introduction including a brief survey on upcoming NVMʹs such as FeRAM, MRAM, 15 CBRAM, PRAM, SONOS, RRAM, Racetrack memory and NRAM. In future Non‐volatile memory 16 may eliminate the need for comparatively slow forms of secondary storage systems, which include 17 hard disks. 18 Keywords: Non‐volatile Memories; NAND Flash Memories; Storage Memories 19 PACS: J0101 20 21 22 1. Introduction 23 Memory is divided into two main parts: volatile and nonvolatile. Volatile memory loses any 24 data when the system is turned off; it requires constant power to remain viable. Most kinds of 25 random access memory (RAM) fall into this category.
    [Show full text]
  • Fast Read/Write • Non-Volatile • Infinite Endurance
    MRAM Magnetoresistive Random Access Memory Fast Read/Write • Non-Volatile • Infinite Endurance High Endurance, Non-volatility Ideal for RAID Applications High Performance, Unlimited En- durance for Industrial and Human Machine Interface Applications Reliability - the Foremost Require- ments in Gaming Systems Performance and Reliability in Demanding Automotive Applications www.everspin.com The MRAM Company Everspin’s State-of-the-Art MRAM Technology How Everspin’s Patented MRAM Memory Technology Works Everspin MRAM is Integrated with Standard CMOS Processing The MTJ device has a low resistance when the magnetic moment of the free layer is parallel to the fixed layer and a high resistance when the free Everspin MRAM is based on magnetic storage elements integrated layer moment is oriented anti-parallel to the fixed layer moment. This with CMOS processing. Each storage element uses a magnetic tun- change in resistance with the magnetic state of the device is an effect nel junction (MTJ) device for a memory cell. known as magnetoresistance, hence the name “magnetoresistive” RAM. Everspin MRAM Technology is Reliable Unlike most other semiconductor memory technologies, the data is stored as a magnetic state rather than a charge, and sensed by measuring The Magnetic Tunnel Junction Storage Element the resistance without disturbing the magnetic state. Using a magnetic state for storage has two main benefits. First, the magnetic polariza- The magnetic tunnel junction (MTJ) storage element is composed tion does not leak away over time like charge does, so the information of a fixed magnetic layer, a thin dielectric tunnel barrier and a free is stored even when the power is turned off.
    [Show full text]