Computer Performance & Storage Devices

Computer Performance& Storage Devices

Computer TechnologyPart 2

Megan ReesElk Ridge Middle

Megan ReesElk Ridge Middle

Computer Performance

Sequence of events that occurs between the time you turn on a computer and the time that it becomes ready to accept commands.◦ Purposes

Runs a diagnostic test to make sure everything is working.

Loading the operating system, so the computer can carry out basic operations.

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Boot Process

Power up Start boot program Power-on self-test Identify peripheral devices Load operation system Check configuration and customization

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6 events of the boot process:

Circuits The path from one

component of a computer to another that data uses to travel.

Circuits run between◦ RAM and the

microprocessor◦ RAM and various

storage devices

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Silicon Chip

Silicon is melted sand.

What the circuits are embedded into to keep them together.

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Megahertz (mHz) A measurement used

to describe the speed of the system clock.

A megahertz is equal to one million cycles (or pulses) per second.

1.3 GHz means that the microprocessor’s clock operates at a speed of 1.3 BILLION cycles per second.

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Pentium Name of the CPU. Pentium is the 5th

generation of the Intel processor.◦ Other generations

were called 80-88 286 386 486

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RAM vs. ROM

RAM ROM

System Crash!

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RAM vs. ROM

RAM RAM

• Random Access Memory• Temporary—content is lost if the

device is powered off• Runs all currently open programs

– the more open programs the slower your computer is

• RAM is rather inexpensive—getting more RAM can speed up your computer. But there is a limit to how much RAM your computer can have.

• Read Only Memory• Permanent Storage• Where all your programs and files

are saved—your hard drive.• The bigger your hard drive, the more

you can save there.• Hard drives rarely crash—anything

saved there is pretty safe—but it’s always good to have backups!

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Binary Number System A method for

representing letters or numbers using only two digits, 0 and 1.◦ Bit

Each 0 or 1◦ Byte

8 bits Also referred to as

Base 2 Binary Code.

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Memory Measurements

Bit ◦ Each 0 or 1

Byte◦ 8 bits

Kilobyte◦ Approximately 1,000

bytes◦ Exactly 1,024 bytes

Megabyte◦ Approximately 1 million

bytes◦ Exactly 1,048,576 bytes

Gigabyte◦ Approximately 1 billion

bytes Terabyte

◦ Approximately 1 trillion bytes

Petabyte, Exabyte, Zettabyte, Zottabyte, Brontobyte

Bit

Byte Kilobyte

MegabyteGigabyteTerabyte

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Storage Devices

Used to keep data when the power to the computer is turned off.

Medium/media◦ Location where data is stored.

Write-Protected - A disk that will not allow a user to make changes to files

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Hard Disk Usually mounted

inside the computer’s system unit.

Can store billions of characters of data.◦ Stated in forms

of bytes: Megabytes or

Gigabytes

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Floppy Disk Round piece of

flexible Mylar plastic covered with a thin layer of magnetic oxide and sealed inside a protective covering.

May be referred to as a “floppy”

3½ disk capacity is 1.44 MB or 1,440,000 bytes

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Zip Disk

Floppy disk technology manufactured by Iomega.◦ Available in 100 MB and 250 MB

versions

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USB Flash Drive Also known as a “Jump Drive.” Typically removable and rewritable,

physically smaller than a floppy.◦ Storage capacities can be as large as

256 GB. Most are 2 to 8 GB. ◦ Smaller, faster, thousands more times

capacity, and are more durable and reliable.

◦ Plug right into a USB port.

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Memory Card

Used for storing digital information, usually for digital camera, mobile phones, laptops, MP3 Players, and video game consoles.◦ Small, re-recordable and can retain data

without power.◦ Usually store from 2 to 8 GB.

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Means of recording data as light and dark spots on CD or DVD.

Reading is done through a low-power laser light.◦ Pits

Dark spots◦ Lands

Lighter, non-spotted surface areas

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Optical Storage

CD-ROM “CD – Read Only

Memory” Also called CD-R

◦ CD-Read Storage device that uses

laser technology to read data that is permanently stored on compact disks, cannot be used to write data to a disk.

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CD-RW

“CD-Read Write” A storage device that reads data from CD’s

and also can write data to CD’s. Similar to a CD-ROM, but has the ability to

write to CD.

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DVD-ROM

“Digital Video Disks – Read Only Memory”

Reads data from CD’s (audio and data) and DVD’s (data or movie)

Cannot be used to write data to a disk.

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Parsons, June Jamrich, and Dan Oja. Computer Concepts. Boston: Course Technology - Thompson Learning, 2002.

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Resources