Storage Devices
Intro
•Most electronic devices need digital
storage.
• It is important to understand the
differences in storage devices and
file sizes before making a purchase.
Objectives
To understand File sizes
 To be able to mentally visualize file sizes
 To understand different storage devices
 To learn how to choose the right storage
device for your needs
 To know the difference between read only
and write
Why is this important?
Knowing this information will help you choose the
right device for your needs.
Knowing how many KB is in a GB, or how many MB
is in a GB will help you in your decision making.
Being able to visualize file size helps you to better
understand the differences.
File Sizes
What is the difference in file sizes?
File size measures the size of a
computer file. This is typically
measured in Bytes.
Bits and Bytes…..delicious
A BIT is the smallest increment of storage
on a computer. Imagine each bit is like a
light bulb. Each one is either on or off, so
it can have one of two values
(either 0 or 1).
A BYTE is a string of 8 bits (eight light
bulbs in a row). A byte is basically the
smallest unit of data that can be
processed on your family computer.
Digital Measurements
A KILOBYTE ( KB) is a unit of approximately 1000
bytes (1024 to be exact). Most download sites use
kilobytes when they give file sizes.
A Megabyte (MB) = 1,048,576 bytes or 1,024
kilobytes. Sometimes used to mean 1 million bytes
Gigabyte (GB)= 1,073,741,824 Approximately 1
billion bytes (1024 MB). Most hard drive sizes are
listed in gigabytes.
Just Keeps Going
A Terabyte = 1024 Gigabytes or
1,099,511,627,776 Bytes
A Petabyte= 1,125,899,906,842,620 Bytes or
1024 terabytes
An Exabyte= 1,152,921,504,606,850,000
Bytes or 1024 Petabytes
A Zettabyte = 1,180,591,620,717,410,000,000
Bytes or 1024 Exabytes
A Yottabyte is 1024 times a zettabyte! Wow!
Simplify
Technically a kilobyte is 1024 but most standards of measurement use
1000 bytes. This chart has exponential numbers, how does that work?
To the Power of:
Exercise
Find the answer to the following:
Answers
Main Points Part 1
• Standard of measurement is Bytes
• 1 Byte = 8 Bits
• Kilo is a prefix meaning 1,000 base of
measurement
• Exponential numbers are the number
times itself x amount of times
Visual Representation Pt 2
•If we took each of these objects and imagined
them to be hollow.
•We are only thinking of the volume each will
hold.
A Bit
( A marble)
8 marbles
would fit in
a baseball
A Byte
( A baseball)
KiloByte
( a pick up
truck)
1,000 baseballs
in the area of a
truck
1,000 trucks in a medium
skyscraper
MegaByte
( A med. Sized
skyscraper)
GigaByte
( 1024
Skyscrapers)
TeraByte
( New York and
Manhattan)
To find out how many MB is in 500 GB, simply multiply
500 X 1000. This equals 500,000. So, 500 GB = 500,000
MB We do this because we know that a GB is 1000 MBs.
To find how many GB = MB, we divide the number
of MB by 1000. So, 800,000 MB divided by 1000 =
800. There are app. 800 GB to 800,000 MB.
Measurement
Size (bytes)
Symbol
Kilobyte
1,000
KB
Megabyte
1,000,000
MB
Gigabyte
1,000,000,000
GB
Terabyte
1,000,000,000,000 TB
Questions
1. There are 1,000 Bytes in a Kilobyte. How many
bytes are in 6 KB?
2. There are 1,000 kilobytes in a Megabyte. How
many KB are in 12 MB?
3. How many bytes are in 12 MB?
4. There are 1,000 MB in a gigabyte. How many GB
are there if you have 365,000 MB?
5. How many KB are there in 6 GB?
Answers
1. 1000 X 6 = 6000. So there are 6,000 bytes in 6
kilobytes
2. 1000 X 12 = 12,000. There are 12,000 KB in 12
MB
3. If there are 12,000 KB in 12 MB, and a KB is 1000
times a byte, then you multiply 12,000 X 1024 =
12,000,000 bytes.
4. You take the # of MB and divide by 1000 to get
the number of GB. 365,000 / 1000 = 365 GB
5. This can be a simple 2 part multiplication problem. We know
that a GB is 1000 times a MB. So we multiply 6 X 1000=
6000. So 6GB=6000 MB. A MB is 1000 times the size of a KB,
so 6000 X 1000 = 6,000,000 KB Answer: 6 GB = 6,000,000
KB.
Photography Project
• Objective: Take original photos of
objects in the room and outside to
represent the following:
•
•
•
•
1 Bit
1 Byte
1 Kilobyte
1 Megabyte
Arrange Photos
• Use the provided template in
Fireworks.
• Place your pictures in the template
• When finished go to File>Save
As>choose .jpg
• Upload your final picture to the gallery
Applying Storage Amounts Pt 3
Physical Storage Vs. Digital
Storage ??
A Typical Page of text is about 4 Kilobytes. 4 KB)
An Amazon Kindle comes with 256 MB of internal
storage, which only 180 MB is available. This can hold
about 200 books.
The average song is about 3,000 to 6,000 KB or 3 to 6
MB
A CD holds about 650-700 MB.
A 20 Gig hard drive will hold the same amount of info
as 31 CDs!
How Much is Enough
• You want to purchase an MP3 player
and there are many choices.
• Your current music library has 4,253
songs, each 4MB in size.
• What is the total size of all the songs?
Music
• The total amount is: 17,012,000 or a
little over 17 gigs.
• This will give us an idea of where we
need to go with our purchase.
• I would recommend a 32 gig player,
20 at the minimum.
Pictures
• You have an extensive photo library
of 850 pictures, 8 megapixels and 3.2
MB each.
• You want to purchase a flash drive so
you need to know how big the current
library is, report your answer.
Photo Answer
• The amount of the current library is:
2,720,000 or 2.7 GB.
• If we purchased a 4GB drive we
would have room to grow and they
are very inexpensive.
Differences in Storage Devices
Pt 4
First, you must know the difference between Read Only and
Read and Write.
Read only Basically means that data is only able to be
“read”. Data cannot be “written” , changed or deleted.
Reading
Writing
Standard Cds and DVDs can be written to once, and
then they become “ read only” Once you burn a
Standard CD, you can no longer make changes to it.
Flash Drives, External hard drives, Internal
hard drives and SD Cards are read and write.
You can add, erase and change data at will.
Flash Drive
Internal Hard Drive
SD Cards
External Hard drive
Different types of storage devices:
1. CD’s (compact disks)
2. CD- RWs
3. DVDs
4. DVD- RWs
5. Flash Drives
6. External hard drives
7. Internal hard drives
CDs
CD-RW
An optical disk used to store digital data. Most
common media is audio. Cd’s hold about 700 MB
of Data
This basically means that the CD can be
erased and re written to multiple times.
DVDs
DVD-RW
An optical disk used to store digital data.
Great for movies and video. DVDs hold about
4.7 GB. That would be app. 4800 MB This is
about 7 times that of a CD!
This basically means that the DVD can be
erased and re written multiple times.
Flash Drives
Also called “ Jump drives”, “ USB Drives”, “
Thumb Drives”, “ Key Chain Drives” and more.
These drives are removable and Rewritable.
They are small in size and can hold between 64
MB to 64 GB. A USB drive does not require
rebooting after it's attached, does not require
batteries or an external power supply, and is not
platform dependent. Several manufacturers
offer additional features such as password
protection, and downloadable drivers that allow
the device to be compatible with older systems
that do not have USB ports.
External Hard Drives
An external hard drive sits outside the main
computer tower, in it’s own hard case. They are
normally connected to your computer by a USB
or Fire wire cable. External hard drives are
compatible for multiple operating systems.
External hard drives
Pros: Have a larger storage capacity
Longer life
Generally holds about 500 GB and up
Cons: These are usually larger in size
Need an external power source
Larger in Size
Portable external hard drives do not require a
power source.
Pros: Normally quite small
Easily portable
Less expensive
Cons: Usually hold smaller amounts of data
They have a shorter life
Fragile
Internal Hard Drives
An internal hard drive hold large amounts of
information inside of the computers‘ structure.
This is the primary storage of your computer. The
hard drive is connected to the motherboard and
must have a power source to work. They have the
fastest transfer rate of all the storage devices.
A typical internal hard drive stores between
320GB and 2TB
Applying What you have learned.
You need a storage device that is portable, able
to read and write and can hold your music
library that is about 2000 MB in size. What will
you buy? Why?
Applying What you have learned.
Answer: You know that 2000 MB = 1.95 GB. I
got this by dividing 2000 by 1000. Since flash
drives are small, able to read and write, and can
hold up to 64 GB, I would probably buy a flash
drive with the storage space I am looking for. I
could also buy a portable external hard drive to
serve the same purpose. Generally, flash drives
cost less.