Transcript Technology In Action

Computer Hardware
Evaluating your system components.
© 2006 Prentice-Hall, Inc.
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System Topics
• To buy or upgrade?
• Evaluating your system:
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CPU
RAM
Storage devices
Video output
Sound systems
Computer ports
• System reliability
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To Buy or To Upgrade?
• Things to consider:
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Moore’s Law – Double every 18 months
Cost of upgrading vs. buying
Time installing software and files
Needs and wants
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Assessing Your Hardware:
Evaluating Your System
• Assess the computer’s subsystems
• The subsystems include:
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CPU
RAM
Storage devices
Video
Audio
Ports
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Evaluating the CPU
• How does the CPU work?
– Control unit – Coordinates activity of components
– Arithmetic logic unit (ALU) – Performs calculations
– Machine cycle: 4 steps
 Fetch - Gets data from RAM
 Decode – Information it can read
 Execute – Executes instruction
 Store – Stores result to RAM
– Speed: Cycles per second
 Mhz – Megahertz 1 million
 Ghz – Gigahertz 1 billion
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Upgrading the CPU
• Expensive – Usually the most expensive
part
• Easy to install
• Motherboard compatibility
• Heat sink and Fan
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Evaluating RAM
• Random access memory (RAM):
– Temporary storage (memory)
– Volatile
• Memory modules:
– SIMM - Single in-line memory module, used in pairs
– DIMM – Dual in-line memory module, one at a time
– RIMM – Rambus in-line memory module
• Types of RAM:
– SRAM – Static, refreshment not needed
– DRAM – Dynamic, refreshment needed
– SDRAM – Synchronous DRAM, synchronizes with CPU
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Adding RAM
• Increase system
performance
• Things to consider:
– Type of RAM module
– Amount of RAM:
 Maximum limit
 Number of slots
 Operating system
 Applications running at the
same time
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Evaluating Storage
• Types of storage devices:
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Hard drive
Floppy drive
Zip disk drive
CD/DVD
Flash memory
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Storing Data
• Magnetic media:
– Metal platters:
Track
 Hard disks
– Plastic film:
 Floppy disks
 Zip disks
• Tracks – Circles
• Sectors - Wedges
• File Allocation Table – Catalog to keep
track of file locations
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Sector
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Storing Data
• Optical media:
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CD ROM
CD-R
CD-RW
DVD ROM
DVD-R
DVD-RW
• Laser
• Pit – 1 micron diameter = 0
• Land - Raised area = 1
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The Hard Disk Drive
• Storage capacity up to
500 GB
• Access time is measured
in milliseconds
Platters
• Data transfer rate is
measured in megabits or
megabytes per second
• Spindle speed is
measured in revolutions
per minute (rpm)
Read/write
head
Access arms
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Portable Storage
• Gives us the ability to move data from one
computer to another
• 4 Types of portable storage devices:
– Floppy disk:
 Capacity 1.44 MB
– Zip disk:
 Capacity 100 MB to 750 MB
– CD-R, CD-RW, DVD-R, DVD-RW:
 Capacity 700 MB to 9.4 GB
– Flash drive:
 Capacity 32 MB to 1 GB
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Upgrading Storage
• Hard drive options:
– Replace current drive with a
larger capacity drive
– Install an additional hard drive
• Other options:
– Zip drive
– Replace CD ROM with CD-R/RW
or DVD-R/RW
– Flash card reader
– Flash memory drive
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Evaluating Video
• Two components:
– Video card (adapter)
– Monitor
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Video Cards
• Process binary data into images
• Contain memory known as video RAM (VRAM)
• Control the number of colors a monitor can
display (bit depth)
– VGA – Video Graphics Array
 4 bits
 16 colors
– True color (SVGA) Super Video Graphics Array
 24 bits (32-bit is the same as a 24 bit color with a 8-bit
alpha channel).
 16 million colors
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Monitors
• Things to consider:
– Types:
 CRT or LCD
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Size:
15, 17, 19, or 21 inch
Can be widescreen
Resolution:
 Increasing resolution allows more
to be displayed
– Dot pitch:
– .31mm or less
– Refresh rate:
 75 Hz or higher
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Evaluating Audio
• Speakers:
– Amplified
– Not amplified
– Sub-woofer
• Sound card:
– Process digital data into
sounds
– 3D sound cards
– Surround sound
 Dolby Digital 5.1
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Evaluating Ports
• Ports are used to connect peripheral
devices to the computer
• Things to consider:
– Devices you want to use
– Ports needed for the devices
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Types of Ports
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Serial
Parallel
Universal serial bus
FireWire
Ethernet
IrDA
Bluetooth
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LPT 1 Port
PS/2
PS/2 Port
Connectors
USB
Ethernet
USB
FireWire
Ethernet
FireWire
Connector
jack
Printer
Connector
Port Cable
Connector
Port
Port
COM 1 Port
Serial
Connector
Transfers
eight
bits
of
data
Transfer
Transfer
rate of
speed
of
100
4 Mbps;
Mbps;
Mbps;
toradio
Uses
Transfer
Transfers
rate
data
1
one
bit
at a
Transfer
rate
ofup
400
Mbps;
simultaneously;
12Mbps
connects
infrared
480Mbps;
light
computers
waves
Hot
swapping
to
networks
waves
time;
send
56Kbps
data
over
short
Digital
cameras
distances
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Adding Ports
• Expansion cards:
– New port standards
• Expansion hubs:
– Enables several
devices to be
connected to a port
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Evaluating System Reliability
• Performance:
– Slow
– Freezes
– Crashes
• Upkeep and maintenance:
– System tools
– Control panel
– Update software and hardware
drivers
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Upkeep and Maintenance
• System tools:
– Disk defragmenter
– Disk cleanup
 Unnecessary files
• Control panel:
– Add/remove programs
– Display
– System
 Device manager
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Update Software and
Hardware Drivers
• Software:
– Automatic updates
– Patches
• Hardware:
– Download updated
drivers
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The Final Decision
• How closely does your system come to
meeting your needs?
• How much would it cost to upgrade your
system?
• How much would it cost to purchase a new
system?
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CPU Topics
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Computer switches
Inside the CPU
Cache memory
Computer buses
Creating faster CPUs
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Digital Data: Switches and Bits
• Electronic switches:
– Vacuum tubes
– Transistors
– Integrated circuits
ON
• Binary number system:
– Representing numbers
– Representing letters and symbols
OFF
 ASCII
 Unicode
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Electronic Switches
• Non-mechanical devices in computers that
open and close circuits
• Types of electronic switches:
– Vacuum tubes
– Transistors:
 Semiconductors
– Integrated circuits
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Switches Representing Data
• The on/off state of a switch represents
one bit of data
• Bit (binary digit):
OFF
ON
– On = 1
– Off = 0
OR
0
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= 1 bit
1
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The CPU: Processing Digital
Information
• CPU components
• Types of CPUs
• What the CPU does:
– Machine cycle:
 System clock
 Cache memory
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The CPU
• Also known as a microprocessor or
processor
• Executes instructions
• Components include:
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Control unit
Arithmetic logic unit (ALU)
Registers – memory storage
Cache memory
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The CPU’s Machine Cycle
• Also known as the processing cycle (4 cycles)
• Fetch:
– The Control Unit searches cache memory and then RAM for
program instructions
– Instructions are moved to the Control Unit
• Decode:
– The Control Unit reads and prepares the program instructions
– The instructions are sent to the ALU
• Execute:
– The ALU performs the calculations
• Store:
– The results are stored in the registers (storage in the CPU)
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Book Example
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The System Clock
• Located on the motherboard
• Controls the CPU’s processing cycles
• Clock cycle:
– Pulse or tick
– Oscillating crystal
• Clock speed:
– Number of pulses per second
– Measured in hertz (Hz)
– Useful for measuring CPUs in the same family
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Cache Memory
• Small amount of memory located on the
CPU chip or near it: used before RAM
– Level 1 is on the CPU and is first
– Level 2 is on or near the CPU and is second
• Stores recent or frequently used
instructions and data
• Used for quick access by the CPU
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Buses: The CPU’s Data Highway
• Bus:
– Electrical pathway used to move data between
components
– Local bus:
 Connects the CPU with the memory
– Expansion bus:
 Connects the CPU with peripheral devices
01100010
01001000
01110011
00100111
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Bus Performance
• Bus clock speed:
– Rate of speed data moves from one location to
another
– Measured in Mhz (millions of clock cycles per second)
• Bus width:
– The number of bits of data moved on a bus at any
one time
– Measured in bits:
 16 bits
 32 bits
 64 bits
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Types of Expansion Buses
• ISA and EISA:
– Found on older computers
– Connects mouse, modem, and sound card
• PCI:
– Faster than ISA and EISA
– Found on modern computers
– Connects network, modem, and sound card
• AGP:
– Used for three-dimensional graphics
– Connects the graphics card and memory
• PCI-Express
– Based on PCI but gets better clock speeds
– Replace PCI and AGP
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Making Computers Faster
• Pipelining:
– The CPU processes more than one instruction at a
time. P4 = 20 pipelines
Non-pipelined CPU
Instruction 1
Fetch
Decode
Execute
Store
Instruction 2
Fetch
Decode
Execute
Store
Pipelined CPU
Instruction 1
Fetch
Decode
Instruction 2
Fetch
Decode
Store
Execute
Store
Fetch
Decode
Execute
Store
Instruction 4
Fetch
Decode
Execute
Instruction 3
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Execute
Store
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Making Computers Faster
• Dual processing:
– Two CPUs on the same
system
– Each processor shares the
workload
Dual processors
• Parallel processing:
– Network of computers
– Each computer works on a
portion of the problem
simultaneously
– SETI
http://setiathome.ssl.berkeley.
edu/
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Lab Assignment
• Build two PCs from Dell
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