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
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
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)
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
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
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
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
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
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)
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)
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
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
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
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
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
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
2K
- 1 ≥ M + K
• Where M is the number of data bits (how many check bits
are required for a byte?)
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=
