understanding the storage of the data structure

understanding

1. Unit III Understanding Storage

2. Types of Storage Hard Disks Flash Memory Storage Cloud Storage Optical Discs Other Types of Storage Putting it All Together

3. Objectives Overview Differentiate between storage devices and storage media Describe the characteristics of an internal hard disk including capacity, platters, read/write heads, cylinders, sectors and tracks, revolutions per minute, transfer rate, and access time Discuss the purpose of network attached storage devices, external and removable hard disks, and hard disk controllers Describe the various types of flash memory storage

4. Objectives Overview Describe cloud storage and explain its advantages Describe the characteristics of optical discs Differentiate among various types of optical discs: CDs, archive discs and Picture CDs, DVDs, and Blu-ray Discs Identify the uses of tape, magnetic stripe cards, smart cards, microfilm and microfiche, and enterprise storage

5. Storage Storage holds data, instructions, and information for future use A storage medium is the physical material on which a computer keeps data, instructions, and information

6. Storage

7. Storage Capacity is the number of bytes a storage medium can hold

8. Storage A storage device is the computer hardware that records and/or retrieves items to and from storage media Reading is the process of transferring items from a storage medium into memory Writing is the process of transferring items from memory to a storage medium

9. Storage Access time measures: The amount of time it takes a storage device to locate an item on a storage medium The time required to deliver an item from memory to the processor

10. Hard Disks A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information

11. Hard Disks Hard disks can store data using longitudinal recording or perpendicular recording

12. Hard Disks Characteristics of a hard disk include: Capacity Platters Read/Write Heads Cylinders Sectors and Tracks Revolutions per Minute Transfer Rate Access Time

13. Hard Disks Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk

14. Hard Disks RAID (redundant array of independent disks) is a group of two or more integrated hard disks A network attached storage (NAS) device is a server connected to a network with the sole purpose of providing storage

15. Hard Disks An external hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly A removable hard disk is a hard disk that you insert and remove from a drive Internal and external hard disks are available in miniature sizes (miniature hard disks)

16. Hard Disks A disk controller consists of a special-purpose chip and electronic circuits that control the transfer of data, instructions, and information from a disk to and from the system bus and other components of the computer SATA EIDE SCSI SAS

17. Flash Memory Storage Flash memory chips are a type of solid state media and contain no moving parts Solid state drives ( SSDs ) have several advantages over magnetic hard disks: Faster access time Faster transfer rates Generate less heat and consume less power Last longer

18. Flash Memory Storage

19. Flash Memory Storage A memory card is a removable flash memory device that you insert and remove from a slot in a computer, mobile device, or card reader/writer CompactFlash (CF) Secure Digital (SD) Secure Digital High Capacity (SDHC) microSD microSDHC xD Picture Card Memory Stick Memory Stick Micro (M2)

20. Flash Memory Storage

21. Flash Memory Storage USB flash drives plug into a USB port on a computer or mobile device

22. Video: Thumb Drive (USB Flash Drive) Encryption

23. Flash Memory Storage An ExpressCard module is a removable device that fits in an ExpressCard slot Developed by the PCMCIA Commonly used in notebook computers

24. Cloud Storage Cloud storage is an Internet service that provides storage to computer users

25. Cloud Storage

26. Cloud Storage Users subscribe to cloud storage for a variety of reasons: Access files from any computer Store large files instantaneously Allow others to access their files View time-critical data and images immediately Store offsite backups Provide data center functions

27. Optical Discs An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser Typically store software, data, digital photos, movies, and music Read only vs. rewritable

28. Optical Discs Optical discs commonly store items in a single track that spirals from the center of the disc to the edge Track is divided into evenly sized sectors

29. Optical Discs Care of optical discs

30. Optical Discs A CD-ROM can be read from but not written to Read from a CD-ROM drive or CD-ROM player A CD-R is a multisession optical disc on which users can write, but not erase A CD-RW is an erasable multisession disc Must have a CD-RW drive

31. Optical Discs Archive disc Stores photos from an online photo center Resolution usually is 7200 pixels per photo Cost is determined by the number of photos being stored Picture CD Single-session CD-ROM that stores digital versions of film Typically uses a 1024 x 1536 resolution Many photo centers offer Picture CD services

32. Optical Discs

33. Optical Discs A DVD-ROM is a high-capacity optical disc on which users can read but not write or erase Requires a DVD-ROM drive A Blu-ray Disc-ROM (BD-ROM) has a storage capacity of 100 GB DVD-RW , DVD+RW , and DVD+RAM are high-capacity rewritable DVD formats

34. Other Types of Storage Tape Magnetic stripe cards and smart cards Microfilm and microfiche Enterprise storage

35. Other Types of Storage Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information A tape drive reads and writes data and information on a tape

36. Other Types of Storage A magnetic stripe card contains a magnetic stripe that stores information A smart card stores data on a thin microprocessor embedded in the card

37. Other Types of Storage Microfilm and microfiche store microscopic images of documents on a roll or sheet film

38. Other Types of Storage

39. Other Types of Storage Enterprise storage stores huge volumes of data and information for large businesses Uses special hardware for heavy use, maximum availability, and maximum efficiency

40. Putting It All Together Home user • 500 GB hard disk • Cloud storage • Optical disc drive • Card reader/writer • USB flash drive Small Office/Home Office user • 1 TB hard disk • Cloud storage • Optical disc drive • External hard disk for backup • USB flash drive Mobile • 250 GB hard disk • Cloud storage • Optical disc drive • Card reader/writer • Portable hard disk for backup • USB flash drive

41. Putting It All Together Power User • 2.5 TB hard disk • Cloud storage • Optical disc drive • Portable hard disk for backup • USB flash drive Enterprise User (desktop computer) • 1 TB hard disk • Optical disc drive • Smart card reader • Tape drive • USB flash drive Enterprise User (server or mainframe) • Network storage server • 40 TB hard disk system • Optical disc server • Microfilm or microfiche

42. Summary Various storage media and storage devices Internal hard disks, external and removable hard disks, solid state drives, memory cards, USB flash drives, ExpressCard modules, cloud storage, CDs, DVDs, and Blu-ray Discs, tape, smart cards, and microfilm and microfiche

43. Central Processing Unit (CPU)

44. Instructions and Data The CPU is the computer’s brain In 1978 had 27,000 transistors now they have over 2.5 billion CPU follows commands called instructions Instruction set is the set of basic commands all CPUs follow Add / subtract Compare Add one to / subtract one from Get the next one, two, or, four bytes from Put the next one, two, or four byte at

45. Instructions and Data The Instruction Set is written in assembly language – the lowest language level used to program a computer. A compiler is a program that translates higher level programs into machine language A register is a small pocket of memory in a CPU used to temporarily store data that is being processed add number stored in register A to number stored in register B place result in register C

46. CPU Operation CPU is in constant operation Refreshing memory Checking for communication from other devices Monitoring system power Performing other programmed duties Checking IRQ status

47. CPU Operation CPU Parts Bus Unit : network of circuitry that connects all off the other major components together Instruction Cache : small temporary memory to store incoming data and instructions Decode unit : decodes instructions Control Unit : controls overall operation of CPU Arithmetic logic unit (ALU) performs math functions Register unit: composed of many separate storage units (register hold only one number or letter each)

48. CPU Operation

49. CPU Operation Not all business conducted on a PC requires the use of a powerful CPU i.e. word processor Powerful CPU needs for graphic intense programs, weather, or CAD programs i.e. 3D animation that requires redrawing every line of image and calculations based on X,Y, & Z coordinates in fractions of a second To save CPU time data not requiring manipulation are now transferred directly to memory System clock send repetitive signal to all parts of system to keep data transmissions in step

50. CPU Operation CPU speed is measured in hertz Hz (cycles per second) Number of digital pulses per second Hertz is often referred to as frequency Speed became important as user interface switched from text to GUI Each new generation of CPU operated on shorter clock cycles (frequency)

51. Enhancing CPU Operation In addition to speed CPU have Improved: Local Bus: links devices directly to CPU RAM Video card slots Referred to as system bus or front side bus Shortened bus reduces inductive reactance Cache L1 cache is designed to run at same speed as CPU L1 allows CPU to quickly process data Two L1 Cache for each processor (one for instruction and one for data) L1 memory is most costly to produce L1 is small on inexpensive processors

52. Enhancing CPU Operation L2 Cache: used to increase data from the processor to other parts of the motherboard Originally separate from CPU mounted close on motherboard Moved in CPU with Pentium III L3 Cache: Originally added to mother board to speed when L2 moved to CPU Now on CPU (shared between multi core CPUs)

53. Enhancing CPU Operation Floating Point Unit (FPU): a set of circuits in the CPU that replace the math coprocessor that was originally on the mother board Multiple Branch Prediction : guesses what data the CPU will need next instead of waiting for instructions to be issued (90% accurate) Superscalar execution : processing more than one instruction at a time

54. Enhancing CPU Operation Dynamic Execution : CPU looks ahead if an instruction can be carried out faster than the instruction preceding it, it is moved ahead an executed. Integrated Memory Controller: (IMC) Controls data flow in front side bus to / from RAM Integrated Graphics Processing : (GPU) enhances the ability of computer to produce video and 3-D images

55. Enhancing CPU Operation Overclocking : running a CPU at frequencies higher than rated. Raises heat Can / will damage CPU CPU can accomplish more tasks in shorter time Frequencies can be controlled by BIOS Turbo Boost Technology / Turbo CORE Overclock CPU Monitor temperature and energy use Halts overclocking if temp gets to high Intel provides free software (Intel Extreme Tuning Utility) Voids warranty Intel does not recommend

56. Process Description Features Reduced Instruction Set Computer (RISC): a CPU Produced with fewer transistors and instruction Inexpensive but fast Software has carry modifications that allow for fewer CPU computations Used in IPad, Iphone, Android, auto engine controls, TVs, airplanes, robots, and servers Complex instruction set computer (CISC): A CPU that processes complex mathematical formulas at increased clock speed

57. Process Description Features MMX Processor : based on standard processor with the addition of 57 commands. 32 bit vs 64 Bit (64 faster.)must have following: BIOS must support 64 bit technology 64 bit O/S 64 bit drivers Software written for 64 bit systems

58. Process Description Features Virtualization : a single physical CPU appear as multiple processors to the system software and the user. Allows multiple operating systems, users, and application software simultaneously Normally applied to network servers System Management Mode : (SMM) Designed for laptops to save energy Sleep Auto shut down

59. Process Description Features Cool ‘n’ Quiet (Process throttling): adjust process speed and power consumption based on temperature and software usage. Fan speed may also be slowed

60. Process Description Features CPU operating voltage has dropped from 5 Volts to less than 1 volt Processor Size (physical) has not changed significantly but the electronics have become more compact

61. Processor Performance CPU is not the only thing that affect system speed Download and Use a CPU analyzer CPU-Z is free Download from Cupid Will identify CPU L1 and L2 size Socket type Core and bus Speed

62. Installing a Processor Remove cooling Device Release locking lever(s) Lift out CPU Align pins (lands) to socket Gently drop CPU into socket Close locking levers Reinstall cooling device

63. Cooling the Processor Electronic integrated circuits start to break down at 160 degrees F Three Type of Cooling Simple heat sink and fan (most common) Heat sink paste Heat pipe cooling system (high performance) Hollow tubes with liquid that vaporizes and condenses at the heat sink and returns to CPU by capillary action Liquid Cooling System (very high performance) Liquid is pumped rom CPU to a small radiator and back to CPU (Most Expensive)

64. Heat Sink and Fan

65. Heat Pipe Cooling System

66. Liquid Cooling System

67. Memory Cell Operation

68. Semiconductor Memory RAM Misnamed as all semiconductor memory is random access Read/Write Volatile Temporary storage Static or dynamic

69. Dynamic RAM Bits stored as charge in capacitors (analogue) Need refresh circuits even when powered Simpler construction Smaller per bit (More dense) Less expensive Slower Main memory

70. Dynamic RAM Structure

71. Static RAM Bits stored as on/off switches (Digital) Does not need refresh circuits More complex construction Larger per bit (Less dense) More expensive Faster Cache memory

72. Static RAM Structure

73. Read Only Memory (ROM) Permanent storage Nonvolatile used in: Microprogramming Library subroutines Systems programs (BIOS) Function tables

74. Types of ROM ROM: Written during manufacture Very expensive for small runs There is no room for error PROM: Programmable (once) ROM needs special equipment to program Read “mostly” Erasable Programmable (EPROM) Erased by UV (more expensive than PROM) Electrically Erasable (EEPROM) Takes much longer to write than read More expensive and less dense than EEPROM Flash memory Intermediate between EPROM and EEPROM in both cost and functionality

75. Semiconductor Memory Types

76. Advanced DRAM Organization Synchronous DRAM Double-data-rate Synchronous DRAM Rambus DRAM Cache DRAM (Integrates small SRAM onto generic DRAM chip)

77. Synchronous DRAM (SDRAM) Access is synchronized with an external clock Address is presented to RAM RAM finds data (CPU waits in conventional DRAM) Since SDRAM moves data in time with system clock, CPU knows when data will be ready CPU does not have to wait, it can do something else Burst mode allows SDRAM to set up stream of data and fire it out in block

78. DDR SDRAM SDRAM can only send data once per clock cycle Double-data-rate SDRAM can send data twice per clock cycle Theoretically DDR module transfer data at a clock rate in the range of 200 to 600 MHz DDR2 module transfers at a clock rate of 400 to 1066 MHz DDR3 module transfers at a clock rate of 800 to 1600 MHz

79. Interleaved Memory Collection of DRAM chips grouped into memory bank Banks independently service read or write requests K banks can service k requests simultaneously To speed up, consecutive words of memory are stored in different banks

80. Memory decoding

81. Two-dimensional decoding

82. Address multiplexing

83. Module Organization A 16Mbit chip can be organized as 1M X16 bit words A bit per chip system has 16 of 1Mbit chips with 1bit of each word (1MX1bit) A 16Mbit chip can be organized as a 2048 x 2048 x 4bit array Reduces number of address pins Multiplex row address and column address

84. 256kByte Module Organization

85. 1MByte Module Organisation

86. Error Correction Hard Failure Permanent defect Soft Error Random, non-destructive No permanent damage to memory Detected using error-correcting code (such as Hamming code)

87. Error Correcting Code Function

88. Hamming Error-Correcting Code

89. Number of check bits the comparison logic receives as input two K-bit values A bit-by-bit comparison is done by taking the exclusive-OR of the two inputs The result is called the syndrome word 2 K - 1 ≥ M + K Where M is the number of data bits (how many check bits are required for a byte?)

90. Hamming code

91. Hamming code characteristics If the syndrome contains all 0s, no error has been detected If the syndrome contains one and only one bit set to 1, then an error has occurred in one of the 4 check bits. No correction is needed If the syndrome contains more than one bit set to 1, then the numerical value of the syndrome indicates the position of the data bit in error. This data bit is inverted for correction

92. Example Correct data 00111001 C1= , C2= , C4= , C8= Stored as Retrieved data 00011001 C1= , C2= , C4= , C8= Syndrome word=

93. RQ: 5.3, 5.4, 5.5, 5.6, 5.7, 5.9, 5.10, 5.11 P: 5.2, 5.3, 5.4, 5.10, 5.11, 5.12, 5.13