Computer Performance& Storage Devices

Computer Technology #2

Computer Performance

Boot Process

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.

6 events of the boot process:

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

customization

Integrated Circuits or Microchips

A tiny complex of electronic components contained on a small wafer or chip

Billions of transistors can be placed on each chip

Computers, cell phones, and all electronic devices use integrated circuits

Silicon Chip

Silicon is melted sand.

The circuits are embedded into silicon

Hertz (not the car rental company)

A measurement used to describe the speed of the system clock, or how fast the computer can complete its tasks.

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

3 GHz (gigahertz) means that the microprocessor’s clock operates at a speed of 3 BILLION cycles per second.

Names of Processors

Processors for Personal Computers are manufactured by Intel (Pentium) and AMD.

Examples: Intel 286 (1982) operated at 12.5 MHz Intel Pentium III (1999) operated at

500 MHz Intel Core 2 (2008) operates at 3.2

GHz AMD Phenom II (2010) operates at

3.2 GHz

Moore’s Law

Gordon Moore, co-founder of Intel, stated in 1965 that transistors in integrated circuits had doubled every year since 1958 and would continue to double at the same rate into the future

Moore’s Law is expected to continue at least until 2015

RAM vs. ROM

RAM “Random Access Memory” The ability of a storage device

to go directly to a specific storage location without having to search sequentially from a beginning location.

Very volatile• Cannot hold data when the

power is off.• Loses all data when power is

lost.

ROM “Read only memory” Drives can read data from

disks, but cannot store new data on them.

One or more integrated circuits that contain permanent instructions that the computer uses during the boot process.

It is not volatile Examples: Music CD’s and

movie DVD’s

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, or about 1 character Also referred to as Base 2

Binary Code or just “digital” Computers cannot

understand anything EXCEPT binary

Memory Measurements Bit

Each 0 or 1 Byte

8 bits (about one character) Kilobyte

Approximately 1,000 bytes Exactly 1,024 bytes About a page of text

Megabyte Approximately 1 million bytes Exactly 1,048,576 bytes About several books

Gigabyte Approximately 1 billion bytes About a pickup full of books

Terabyte Approximately 1 trillion bytes About 50,000 trees turned into paper and

printed

Storage Devices

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

Medium/media Location where data is stored.

Hard Disk It is the most important

storage device Usually mounted inside

the computer’s system unit.

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

bytes: Gigabytes or

terabytes Hard disk capacity also

follows Moore’s Law

Magnetic Storage

Recording of data onto disks or tape by magnetizing particles of an oxide based surface coating.

A fairly permanent type of storage that can be modified.

The hard disk is magnetic

Optical Storage

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

CD-ROM

“Compact Disk – Read Only Memory”

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.

The data cannot be changed

CD-R and CD-RW

“Compact Disk-Read Write” A storage device that reads

data from CD’s and also can write data (or save data) to CD’s.

CD-Rs can be written to one time only

CD-RWs can be written to more than once

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.

There are also DVD-Rs and DVD-RWs, which can write data to a DVD

Solid State Storage Sometimes called “flash drives” or

USB drives Holds up to 256 GB of data (2010) Can be used on any computer with a

USB port Making most other storage devices

obsolete

External Hard Drives

Can be plugged into any USB port

Will allow you to take your data with you

Cloud Computing

Cloud computing is a way to store your data on a server on the Internet and access it from any location

Yahoo mail (or other e-mail) is a simple example of cloud computing (you can store and access your mail from any computer)