Chapter 6: Understanding and Assessing Hardware 1
Chapter 6 Chapter 6 –– Part 1Part 1Understanding HardwareUnderstanding Hardware
CS10001CS10001-- Computer LiteracyComputer Literacy
Chapter 6: Understanding and Assessing Hardware 2
System EvaluationSystem Evaluation
The subsystems to understand:The subsystems to understand: CPU subsystemCPU subsystem
Memory subsystemMemory subsystem
Storage subsystem Storage subsystem
Video subsystemVideo subsystem
Audio subsystemAudio subsystem
Port subsystemPort subsystem
Chapter 6: Understanding and Assessing Hardware 3
The CPU SubsystemThe CPU Subsystem
Recall that the Recall that the CPU is the CPU is the ““brainsbrains”” of the of the computer and computer and processes userprocesses user--defined input defined input into information.into information.
Chapter 6: Understanding and Assessing Hardware 4
The CPU SubsystemThe CPU Subsystem
The CPUThe CPU’’s responsibilities s responsibilities include:include: Processing instructionsProcessing instructions
Performing calculationsPerforming calculations
Managing the flow of information Managing the flow of information through the computer systemthrough the computer system
Chapter 6: Understanding and Assessing Hardware 5
The CPU SubsystemThe CPU Subsystem
Two components do the workTwo components do the work The The control unitcontrol unit coordinates all coordinates all
the computer componentsthe computer components’’activities.activities.
The The arithmetic logic unit (ALU)arithmetic logic unit (ALU)performs the arithmetic calculations performs the arithmetic calculations and makes logic and comparison and makes logic and comparison decisions.decisions. Add, subtract, multiply, divideAdd, subtract, multiply, divide >, <, =, not equal >, <, =, not equal
Chapter 6: Understanding and Assessing Hardware 6
The CPU SubsystemThe CPU Subsystem The The machine cyclemachine cycle is the steps taken is the steps taken
by the CPU while processing by the CPU while processing instructions.instructions. Instruction cycleInstruction cycle
FetchesFetches the data or instruction from RAMthe data or instruction from RAM DecodesDecodes the instruction into useable machine the instruction into useable machine
formatformat
Execution cycleExecution cycle ExecutesExecutes the instruction after understanding the instruction after understanding
the instructionthe instruction StoresStores the instruction result in RAMthe instruction result in RAM
Chapter 6: Understanding and Assessing Hardware 7
The CPU SubsystemThe CPU Subsystem
Clock speedClock speed is the speed or is the speed or pace of machine cycles as pace of machine cycles as determined by the system clock. determined by the system clock. The pace is steady, constant and The pace is steady, constant and
extremely fast.extremely fast. The CPUThe CPU’’s speed is measured in s speed is measured in
Hertz (Hz) which is Hertz (Hz) which is ““machine cycles machine cycles per secondper second””.. MHz (1M Hz) and GHz (1B Hz)MHz (1M Hz) and GHz (1B Hz)
Chapter 6: Understanding and Assessing Hardware 8
The Memory SubsystemThe Memory Subsystem
Recall that RAM is Recall that RAM is volatilevolatilestorage. It remains accessible storage. It remains accessible while the computer is running but while the computer is running but disappears when the computer is disappears when the computer is turned off.turned off.
RAM holds all the instructions RAM holds all the instructions and data needed by the CPU as and data needed by the CPU as well as the operating system.well as the operating system.
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The Memory SubsystemThe Memory Subsystem
The CPU uses RAM to access The CPU uses RAM to access data and instructions because it data and instructions because it is faster than accessing data and is faster than accessing data and instructions from the hard disk instructions from the hard disk (nanoseconds vs. milliseconds).(nanoseconds vs. milliseconds).
RAM is located on the RAM is located on the motherboard, in memory modules motherboard, in memory modules (memory cards).(memory cards).
What else is located on the motherboard with RAM?
Chapter 6: Understanding and Assessing Hardware 10
The Memory SubsystemThe Memory Subsystem
Virtual memoryVirtual memory is a small is a small amount of memory on the hard amount of memory on the hard disk that is dedicated to storing disk that is dedicated to storing data and instructions when RAM data and instructions when RAM runs out.runs out.
A A page filepage file or or swap fileswap file is is created on the hard disk and it created on the hard disk and it stores the data and instructions.stores the data and instructions.
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The Memory SubsystemThe Memory Subsystem
If files are created on the hard If files are created on the hard drive, why not just use the hard drive, why not just use the hard drive instead of RAM or virtual drive instead of RAM or virtual memory?memory? SpeedSpeed is the single biggest reasonis the single biggest reason
Some applications do not run well Some applications do not run well in virtual memoryin virtual memory
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The Storage SubsystemThe Storage Subsystem
Recall that the hard disk drive is Recall that the hard disk drive is the largest nonvolatile storage the largest nonvolatile storage unitunit
Other permanent storage units Other permanent storage units include:include: Floppy disksFloppy disks ZIP disksZIP disks Flash drivesFlash drives CD/DVD drivesCD/DVD drives
Chapter 6: Understanding and Assessing Hardware 13
The Storage SubsystemThe Storage Subsystem Why are hard disk drives so popular?Why are hard disk drives so popular?
Offer the largest amount of permanent Offer the largest amount of permanent storage (nonvolatile)storage (nonvolatile)
Provide the fastest Provide the fastest access timeaccess time (the (the time needed for a storage device to locate time needed for a storage device to locate and retrieve its stored data) in and retrieve its stored data) in millisecondsmilliseconds
Provide the fastest Provide the fastest data transfer ratedata transfer rate(the speed at which data is transferred to (the speed at which data is transferred to other computer components, particularly other computer components, particularly RAM) in megabits or megabytesRAM) in megabits or megabytes
Chapter 6: Understanding and Assessing Hardware 14
The Storage SubsystemThe Storage Subsystem
Hard disk drives (in detail)Hard disk drives (in detail) PlattersPlatters
Round, thin plates of metal (iron Round, thin plates of metal (iron oxide)oxide)
Divided into Divided into trackstracks (concentric circles)(concentric circles) Then into Then into sectorssectors (pie(pie--shaped shaped
wedges)wedges) Then into Then into clustersclusters (smallest sector (smallest sector
segments)segments)
The spindle is the storage place for stacked platters.
Chapter 6: Understanding and Assessing Hardware 15
The Storage SubsystemThe Storage Subsystem
Hard disk drives (in detail)Hard disk drives (in detail)
Platters
Where are the
Tracks?
Sectors?
Clusters?
Data is stored in magnetized spots, 1=data, 0=space
Spindle
Chapter 6: Understanding and Assessing Hardware 16
The Storage SubsystemThe Storage Subsystem
Hard disk drives (in detail)Hard disk drives (in detail)
What else about platters?What else about platters?
They spin at high rates of speed, They spin at high rates of speed,
usually between 5400 rpm and usually between 5400 rpm and
7200 rpm (revolutions per 7200 rpm (revolutions per
minute)minute)
Chapter 6: Understanding and Assessing Hardware 17
The Storage SubsystemThe Storage Subsystem
Hard disk drives (in detail)Hard disk drives (in detail) Access Arms
Read/write heads
Special access arms sit between the platters and at the end of the access arms are the read/write heads.
Chapter 6: Understanding and Assessing Hardware 18
The Storage SubsystemThe Storage Subsystem
Read/write heads (in detail)Read/write heads (in detail) Do not physically touch the platters, Do not physically touch the platters,
they float above the surfacesthey float above the surfaces Retrieve and record data to and Retrieve and record data to and
from the hard diskfrom the hard disk Start at the outer edge of the Start at the outer edge of the
spinning platters and move towards spinning platters and move towards the centerthe center
This process is the access time. Average access time 10ms.
Chapter 6: Understanding and Assessing Hardware 19
The Storage SubsystemThe Storage Subsystem
Read/write heads (in detail)Read/write heads (in detail) Access time is a combination of two Access time is a combination of two
factorsfactors Seek timeSeek time is the time taken by the is the time taken by the
read/write heads to locate the proper read/write heads to locate the proper tracktrack
LatencyLatency is the time taken for the is the time taken for the correct sector to spin to the read/write correct sector to spin to the read/write headsheads
Chapter 6: Understanding and Assessing Hardware 20
The Storage SubsystemThe Storage Subsystem
Read/write heads (in detail)Read/write heads (in detail) A A head crashhead crash occurs when dust or occurs when dust or
dirt is located between the dirt is located between the read/write heads and the disk read/write heads and the disk platters.platters.
Results in hard disk drive stoppageResults in hard disk drive stoppage
Results in data lossResults in data loss
Chapter 6: Understanding and Assessing Hardware 21
The Storage SubsystemThe Storage Subsystem SpecificationSpecification
Mfr Part Number: WD1600AAJS Mfr Part Number: WD1600AAJS Capacity: 160 GB Capacity: 160 GB Rotational Speed: 7200 rpm Rotational Speed: 7200 rpm Cache: 8 MB Cache: 8 MB Interface: SATA 300 Interface: SATA 300 Max. External Transfer Rate: 300 MB/s Max. External Transfer Rate: 300 MB/s Seek Time: Seek Time:
Track to Track: 2 ms Track to Track: 2 ms Average: 8.9 ms (read)Average: 8.9 ms (read) Full Stroke: 21 ms Full Stroke: 21 ms
Shock: Shock: Operating: 65G @ 2ms Operating: 65G @ 2ms NonNon--operating: 300G @ 2ms operating: 300G @ 2ms
Dimensions (WxLxH): 4 x 5.787 x 1.028 inch / 101.6 x Dimensions (WxLxH): 4 x 5.787 x 1.028 inch / 101.6 x 147 x 26.1 mm 147 x 26.1 mm
Weight: 1.32 lbs / 0.6 kg Weight: 1.32 lbs / 0.6 kg
http://www.ewiz.com/detail.php?p=HD-W1600AS&c=pw
Chapter 6: Understanding and Assessing Hardware 22
The Video SubsystemThe Video Subsystem
Two main componentsTwo main components Video cardVideo card or or video adaptervideo adapter
Expansion cardExpansion card
VRAM for graphics processing redirection from VRAM for graphics processing redirection from the CPUthe CPU
Translates binary data into imagesTranslates binary data into images
Controls the number of colors displayed by the Controls the number of colors displayed by the monitormonitor
MonitorMonitor
Chapter 6: Understanding and Assessing Hardware 23
The Audio SubsystemThe Audio Subsystem
Two main componentsTwo main components Sound cardSound card
Expansion cardExpansion card Processes digital data into soundsProcesses digital data into sounds Produces the sounds through the Produces the sounds through the
speakersspeakers
SpeakersSpeakers Amplified Amplified –– uses external poweruses external power Unamplified Unamplified –– uses internal poweruses internal power
Chapter 6: Understanding and Assessing Hardware 24
The Port SubsystemThe Port Subsystem
PortsPorts are interfaces used to connect are interfaces used to connect external devices to your computer.external devices to your computer.
Five common types of ports:Five common types of ports: SerialSerial ParallelParallel USBUSB FireWireFireWire EthernetEthernet
Chapter 6: Understanding and Assessing Hardware 25
The Port SubsystemThe Port Subsystem
SerialSerial ports ports transfer one bit transfer one bit at a time at at a time at speeds up to speeds up to 56Kbps56Kbps
COM 1 Port
Serial connector
PS/2 Port and connector
Chapter 6: Understanding and Assessing Hardware 26
The Port SubsystemThe Port Subsystem
ParallelParallel ports ports transfer transfer groups of bits groups of bits at a time with at a time with speeds up to speeds up to 12Mbps12Mbps
LPT 1 Port
Printer Cable Connector
Chapter 6: Understanding and Assessing Hardware 27
The Port SubsystemThe Port Subsystem
USB USB (universal (universal serial bus)serial bus)ports transfer ports transfer mass data up mass data up to 480Mbpsto 480Mbps
USB Port
USB Connector
Chapter 6: Understanding and Assessing Hardware 28
The Port SubsystemThe Port Subsystem
FireWireFireWire ports ports transfer mass transfer mass data between data between 400400--800Mpbs800Mpbs
Also knows as Also knows as IEEE1394 IEEE1394
Digital Digital cameras cameras
FireWire Port
FireWire Connector
Chapter 6: Understanding and Assessing Hardware 29
The Port SubsystemThe Port Subsystem
EthernetEthernet ports ports transfer between transfer between 100100--1000Mbps1000Mbps
Fast or Gigabit Fast or Gigabit EthernetEthernet
Used to connect Used to connect computers to a computers to a local network or local network or cable modemcable modem
Ethernet Port
Ethernet jack
Chapter 6: Understanding and Assessing Hardware 30
Chapter 6 Chapter 6 –– Part 2Part 2Evaluating HardwareEvaluating Hardware
CS10001CS10001-- Computer LiteracyComputer Literacy
Chapter 6: Understanding and Assessing Hardware 31
Evaluating the CPUEvaluating the CPU To identify your CPUTo identify your CPU’’s s
speed from Windows speed from Windows XP:XP: Start Start My My
ComputerComputer
Select Select Hard Disk Hard Disk DriveDrive
Under Under System TasksSystem Taskson the left, select on the left, select ““View System View System InformationInformation””
General TabGeneral Tab
Chapter 6: Understanding and Assessing Hardware 32
Evaluating the CPUEvaluating the CPU To identify your To identify your
CPUCPU’’s usage from s usage from Windows XP:Windows XP: RightRight--click empty click empty
area of the taskbararea of the taskbar
Select Select Task Task ManagerManager
Performance TabPerformance Tab
Want to stay under Want to stay under 90%90%
Chapter 6: Understanding and Assessing Hardware 33
Evaluating the RAMEvaluating the RAM To identify your To identify your
systemsystem’’s RAM or s RAM or physical memoryphysical memory:: RightRight--click empty click empty
area of the taskbararea of the taskbar
Select Select Task Task ManagerManager
Performance TabPerformance Tab
Total installedTotal installed
Total availableTotal available
Chapter 6: Understanding and Assessing Hardware 34
Evaluating the VMEvaluating the VM To identify your To identify your
systemsystem’’s virtual s virtual memory:memory: RightRight--click empty click empty
area of the taskbararea of the taskbar
Select Select Task Task ManagerManager
Performance TabPerformance Tab
Want to stay < Want to stay < 1.5% of total RAM1.5% of total RAM
Chapter 6: Understanding and Assessing Hardware 35
Evaluating the VideoEvaluating the Video To identify the type of To identify the type of
video card in your system:video card in your system:
At the Desktop, rightAt the Desktop, right--
click click
Select Select PropertiesProperties
At the At the ““Display Display
PropertiesProperties”” dialog box, dialog box,
select the Settings tabselect the Settings tab
Click the Advanced Click the Advanced
buttonbutton
Adapter tabAdapter tab
Chapter 6: Understanding and Assessing Hardware 36
Evaluating the VideoEvaluating the Video
To evaluate your systemTo evaluate your system’’s s monitor:monitor:
Consider CRT vs. LCDConsider CRT vs. LCD
Consider size: 15Consider size: 15””, 17, 17””, 19, 19””
Consider refresh rateConsider refresh rate
Adjust screen resolutionAdjust screen resolution
Chapter 6: Understanding and Assessing Hardware 37
Evaluating the AudioEvaluating the Audio
Read about speakers and sound Read about speakers and sound cards on pp. 269cards on pp. 269--270.270.
Chapter 6: Understanding and Assessing Hardware 38
Evaluating the PortsEvaluating the Ports
Read about IrDA, Bluetooth and Read about IrDA, Bluetooth and MIDI on pp. 272MIDI on pp. 272--273.273.
Expansion hubsExpansion hubs are devices are devices that connect to one port (usually that connect to one port (usually USB) and provide new ports to be USB) and provide new ports to be usedused FireWire FireWire 2 and USB 2 and USB 44
Chapter 6: Understanding and Assessing Hardware 39
Evaluating ReliabilityEvaluating Reliability
Clean out the Startup folderClean out the Startup folder pp. 274pp. 274--275275
Clear out unnecessary filesClear out unnecessary files Use the Disk Cleanup utilityUse the Disk Cleanup utility
Run antiRun anti--virus and antivirus and anti--spyware spyware programsprograms
Reorganize your hard drive spaceReorganize your hard drive space Use the Disk Defragmenter utilityUse the Disk Defragmenter utility