1.1.1 Computer cases are typically made of plastic, steel, or aluminum and are available in a
variety of styles.cases also provide an environment designed to keep the internal
components cool. All computers need a power supply to convert alternating-current (AC)
power from the wall socket into direct-current (DC) power.The motherboard is the main
circuit board in a computer.The size and shape of the computer case is usually determined
by the motherboard, power supply, and other internal components. The specifications and
dimensions of these components is called the form factor.
1.1.2 Several factors while choosing a case:
188.8.131.52 Size of the motherboard.
184.108.40.206 Available space.
220.127.116.11 Number of external or internal drive locations, called bays.
1.2 Power Supply
1.2.1 The power supply converts Alternating Current (AC) power into
Direct Current (DC) power. DC power is required for all
components inside the computer. An uninterruptible power
supply (UPS) can protect a computer from problems caused
by changes in power. A UPS uses a power inverter. A power
inverter provides AC power to the computer from a built-in
battery by converting the DC current of the UPS battery into
AC power. This built-in battery is continually charged via DC
current that is converted from the AC supply.
18.104.22.168 There are 3 main form factors for power supplies, Advanced
Technology (AT), AT Extended (ATX), and ATX12V. The ATX12V is
the most common form factor used in computers today.
22.214.171.124 A Berg keyed connector connects to a floppy drive.
A Berg connector is smaller than a Molex connector.
126.96.36.199 A SATA keyed connector connects to an optical drive or a hard drive.
The SATA connector is wider and thinner than a Molex connector.
188.8.131.52 A Molex keyed connector connects to optical drives,
hard drives, or other devices that use older technology.
184.108.40.206 A 20-pin or 24-pin slotted connector connects to the motherboard. The 24-pin connector
has two rows of 12 pins each, and the 20-pin connector has two rows of 10 pins each.
220.127.116.11 A 4-pin to 8-pin auxiliary power connector has two rows of two to four pins and supplies power to all
areas of the motherboard. The auxiliary power connector is the same shape as the main power
connector but smaller. It can also power other devices within the computer.
18.104.22.168 A 6/8-pin PCIe power connector has two rows of three to four pins and supplies power to other
22.214.171.124 Older standard power supplies used two connectors called P8 and P9 to connect to the
motherboard. P8 and P9 were unkeyed connectors
1.3 Electricity and Ohm's Law
1.3.1 Basic units of electricity:
126.96.36.199 Voltage: It is measured in volts (V).
188.8.131.52 Current: It is measured in amperes, or amps (A).
184.108.40.206 Resistance (R)
220.127.116.11 Power: It is measured in watts(W)
18.104.22.168 Basic equation
22.214.171.124.1 V = IR
126.96.36.199.2 P = VI
188.8.131.52.3 I = P/V
2 Internal PC Components
2.1.1 It is the main printed circuit board and contains the buses, or
electrical pathways, found in a computer.These buses allow data to
travel between the various components that comprise a computer. A
motherboard is also known as the system board or the main board.
2.1.2 An important set of components on the motherboard is the
chipset. The chipset is composed of various integrated circuits
attached to the motherboard. They control how system hardware
interacts with the CPU and motherboard.
2.1.3 Most chipsets are divided into
two distinct components:
184.108.40.206.1 Northbridge controls access to the RAM, video
card, and the speeds at which the CPU can
communicate with them. The video card is
sometimes integrated into the Northbridge.
220.127.116.11.1 Southbridge allows the CPU to communicate with the
hard drive, sound card, USB ports, and other I/O ports.
2.2.1 The central processing unit (CPU) is considered the brain of the
computer. It is sometimes referred to as the processor. Most calculations
take place in the CPU.CPU is the most important element of a computer
system. CPUs come in different form factors.Common CPU manufacturers
include Intel and AMD. Current processors use a 32-bit or 64-bit FSB.
Overclocking is a technique used to make a processor work at a faster
speed than its original specification. The amount of data that a CPU can
process at one time depends on the size of the front side bus (FSB).
2.2.2 These CPUs are capable of processing multiple instructions concurrently:
18.104.22.168 Single Core CPU - One core inside a single CPU that handles all the processing. A motherboard
manufacturer might provide sockets for more than one single processor, providing the ability to
build a powerful, multiprocessor computer.
22.214.171.124 Dual Core CPU - Two cores inside a single CPU in which both cores can process information at the same
126.96.36.199 Triple Core CPU - Three cores inside a single CPU that is actually a quad-core processor with one of the
188.8.131.52 Hexa-Core CPU - Six cores inside a single CPU.
184.108.40.206 Quad Core CPU - Four cores
inside a single CPU.
220.127.116.11 Octa-Core CPU - Eight cores inside a
2.3 Cooling system
2.3.1 A case fan installed in the computer case makes the
cooling process more efficient. In addition to a case fan, a
heat sink draws heat away from the CPU core. A fan on
top of the heat sink moves the heat away from the CPU.
Computers with extremely fast CPUs and GPUs might use
a water-cooling system.
2.4.1 Read-only memory (ROM) chips are located on the
motherboard and other circuit boards. ROM is sometimes
called firmware.A ROM chip cannot be erased or re-written
and is obsolete. Types of ROM:
18.104.22.168 Programmable read-only memory. Information is written
to a PROM chip after it is manufactured. A PROM chip
cannot be erased or re-written.
22.214.171.124 Erasable programmable read-only memory. Information is written
to an EPROM chip after it is manufactured. An EPROM chip can be
erased with exposure to UV light. Special equipment is required.
126.96.36.199 Electrically erasable programmable read-only memory. Information
is written to an EEPROM chip after it is manufactured. EEPROM
chips are also called Flash ROMs. An EEPROM chip can be erased
and re-written without having to remove the chip from the computer.
2.5.1 RAM is the temporary storage for data and programs that are being
accessed by the CPU. RAM is volatile memory, which means that the
contents are erased when the computer is powered off. Types of RAM
188.8.131.52 Dynamic RAM is a memory chip that is used as main memory.
DRAM must be constantly refreshed with pulses of electricity in order
to maintain the data stored within the chip.
184.108.40.206 Static RAM is a memory chip that is used as cache memory. SRAM is much faster
than DRAM and does not have to be refreshed as often. SRAM is much more
expensive than DRAM.
220.127.116.11 Fast Page Mode DRAM is memory that supports paging. Paging enables faster access to
the data than regular DRAM. FPM memory was used in Intel 486 and Pentium systems.
18.104.22.168 Extended Data Out RAM is memory that overlaps consecutive data accesses. This speeds up
the access time to retrieve data from memory, because the CPU does not have to wait for one
data access cycle to end before another data access cycle begins.
22.214.171.124 Synchronous DRAM is DRAM that operates in synchronization with the memory bus. The
memory bus is the data path between the CPU and the main memory. Control signals are used
to coordinate the exchange of data between SDRAM and the CPU.
126.96.36.199 Double Data Rate SDRAM is memory that transfers data twice as fast as SDRAM. DDR SDRAM increases
performance by transferring data twice per clock cycle.
188.8.131.52 RAMBus DRAM is a memory chip that was
developed to communicate at very high rates of
speed. RDRAM chips are not commonly used.
184.108.40.206 Double Data Rate 3 SDRAM expands memory bandwidth by doubling the clock rate of DDR2 SDRAM. DDR3
SDRAM consumes less power and generates less heat than DDR2 SDRAM.
220.127.116.11 Double Data Rate 2 SDRAM is a faster than
DDR-SDRAM memory. DDR2 SDRAM improves
performance over DDR SDRAM by decreasing
noise and crosstalk between the signal wires.
2.6 Memory Modules
2.6.1 Memory modules can be single-sided or double-sided.
Single-sided memory modules contain RAM only on one
side of the module. Double-sided memory modules contain
RAM on both sides. Different types of memory modules
18.104.22.168 Dual Inline Package is an individual memory chip. A DIP has dual
rows of pins used to attach it to the motherboard.
22.214.171.124 Single Inline Memory Module is a small circuit board that holds
several memory chips. SIMMs have 30-pin or 72-pin configurations.
126.96.36.199 Dual Inline Memory Module is a circuit board that holds SDRAM, DDR
SDRAM, DDR2 SDRAM, and DDR3 SDRAM chips. There are 168-pin
SDRAM DIMMs, 184-pin DDR DIMMs, and 240-pin DDR2 and DDR3 DIMMs.
188.8.131.52 RAMBus Inline Memory Module is a circuit board that holds
RDRAM chips. A typical RIMM has a 184-pin configuration.
184.108.40.206 RAMBus Inline Memory Module is a circuit board that holds
RDRAM chips. A typical RIMM has a 184-pin configuration.
220.127.116.11 Static RAM (SRAM) is used as cache memory to store the
most recently used data and instructions. SRAM provides the
processor with faster access to the data than retrieving it from
the slower dynamic RAM (DRAM), or main memory.
18.104.22.168.1 L1 cache is internal cache and is integrated into the CPU.
22.214.171.124.2 L2 cache is external cache and was originally mounted on
the motherboard near the CPU. L2 cache is now integrated
into the CPU.
126.96.36.199.3 L3 cache is used on some high-end workstations and
2.6.3 Error Checking
188.8.131.52 Memory errors occur when the data is not stored correctly in the RAM chips.
184.108.40.206.1 Nonparity memory does not check for errors
220.127.116.11.2 Parity memory contains eight bits for data
and one bit for error checking. The
error-checking bit is called a parity bit.
18.104.22.168.3 Error Correction Code memory can detect
multiple bit errors in memory and correct
single bit errors in memory.
2.7 Adapter Cards and Expansion Slots
2.7.1 Adapter cards increase the functionality of a computer by adding
controllers for specific devices or by replacing malfunctioning ports.
22.214.171.124 Some common adapter cards that are used to expand and customize the capability of a computer:
126.96.36.199.1 NIC Card
188.8.131.52.2 Wireless NIC
184.108.40.206.3 Sound adapter
220.127.116.11.4 Video adapter
18.104.22.168.5 Capture card
22.214.171.124.6 TV tuner card
126.96.36.199.7 Modem adapter
188.8.131.52.8 Small Computer System Interface (SCSI) adapter
184.108.40.206.9 Redundant Array of Independent Disks (RAID) adapter
220.127.116.11.10 Universal Serial Bus (USB) port
18.104.22.168.11 Serial port
22.214.171.124.12 Parallel port
2.7.2 The different types of expansion slots:
126.96.36.199 PCI - X
188.8.131.52 Mini PCI
2.8 Storage Devices and Raid
2.8.1 Some storage drives can connect to the computer using a USB port, a FireWire
port, eSATA, or a SCSI port. Here are some common types of storage drives:
184.108.40.206 A floppy drive, or floppy disk drive, is a storage device that uses removable
3.5-inch floppy disks. Can store 720 KB or 1.44 MB of data. The floppy drive is
usually configured as the A: drive. The floppy drive can be used to boot the
computer if it contains a bootable floppy disk.
220.127.116.11 A hard drive, or hard disk drive, is a magnetic device used to store
data. The hard drive is usually configured as the C: drive.The storage
capacity of a hard drive ranges from gigabytes (GB) to terabytes
(TB). The speed of a hard drive is measured in revolutions per
minute (RPM). You can replace a magnetic drive with an SSD.
18.104.22.168 Magnetic tapes are most often used for backups or archiving
data. The tape uses a magnetic read/write head. Common tape
capacities vary between a few gigabytes to many terabytes.
22.214.171.124 An optical drive uses lasers to read data on the optical media. There
are three types of optical drives:
126.96.36.199.1 Compact disc (CD)
188.8.131.52.2 Digital versatile disc (DVD)
184.108.40.206.3 Blu-ray disc (BD)
2.8.2 RAID provides a way to store data across multiple hard
disks for redundancy.The following terms describe how
RAID stores data on the various disks:
220.127.116.11 Parity - Detects data errors.
18.104.22.168 Striping - Writes data across multiple drives.
22.214.171.124 Mirroring - Stores duplicate data on a second drive.
2.9 Internal Cables
2.9.1 A power supply might have SATA power connectors for SATA drives, Molex
power connectors for PATA drives, and Berg connectors for floppy drives.
Here are some common types of data cables:
126.96.36.199 Floppy disk drive (FDD) data cable - Has up to two 34-pin drive
connectors and one 34-pin connector for the drive controller.
188.8.131.52 PATA (IDE/EIDE) 40-conductor data cable - The 40-conductor
ribbon cable uses 40-pin connectors. The cable has two
connectors for the drives and one connector for the controller.
184.108.40.206 PATA (EIDE) 80-conductor data cable - As the data rates available over
the EIDE interface increased, the chance of data corruption during
transmission increased. The 80-conductor cable uses 40-pin
220.127.116.11 SATA data cable - This cable has seven
conductors, one keyed connector for the drive, and
one keyed connector for the drive controller.
18.104.22.168 SCSI data cable - There are three types of SCSI data cables. A narrow SCSI data
cable has 50 conductors, up to seven 50-pin connectors for drives, and one 50-pin
connector for the drive controller, also called the host adapter. A wide SCSI data
cable has 68 conductors, up to 15 68-pin connectors for drives, and one 68-pin
connector for the host adapter. An Alt-4 SCSI data cable has 80 conductors, up to 15
80-pin connectors for drives, and one 80-pin connector for the host adapter.
3 CAx Workstations
3.1 CAx is used to develop the computer parts used in CAx workstations. A
computer used to run CAx software must support the needs of the software
and the I/O devices. CAx software is often complex and requires robust
hardware. Consider the following hardware when you need to run CAx software:
3.1.1 Powerful processor - CAx software must make enormous
amounts of calculations very quickly. You must meet the
needs of the software when choosing a CPU.
3.1.2 High-end video card - Some CAx software is used to create 3D models.
Realistic shading and texturing add to the complexity of the models, and
a video card that can handle high resolutions and high detail is needed.
3.1.3 RAM - Because of the high amount of data processed by a CAx workstation, RAM
is very important. The more RAM that is installed, the more data the processor can
calculate before needing to read from slower storage, such as hard drives.
3.2 Audio and Video Editing Workstations
3.2.1 An audio and video editing workstation is used during many stages of development when creating audio and video
material. An audio editing workstation is used to record music, create music CDs, and CD labels. A video editing
workstation can be used to create television commercials, prime-time programming, and movies for the theater or
home movies.Consider the following hardware when you need to run audio and video editing software:
22.214.171.124 Specialized audio card - When recording music to a computer in a studio,
multiple inputs from microphones and many outputs to effects equipment
may be needed. An audio card capable of handling all these inputs and
outputs is needed. Research different audio card manufacturers and
understand the needs of your customer to install an audio card that will meet
all the needs of a modern recording or mastering studio.
126.96.36.199 Specialized video card - A video card that can
handle high resolutions and multiple displays is
necessary to combine and edit different video feeds
and special effects in real time. You must
understand the needs of the customer and
research video cards to install a card that can
handle the high amounts of information that comes
from modern cameras and effects equipment.
188.8.131.52 Large, fast hard drive - Modern video cameras record in high resolution at fast
frame rates. This translates into a high amount of data. A large, fast hard drive is
necessary to record high-end video without errors or missed frames. RAID levels
such as 0 or 5, where striping is used, can help to increase storage speed.
184.108.40.206 Dual monitors - When working with audio and video, three, or even
more monitors can be very helpful to keep track of everything that is
going on with multiple tracks, scenes, equipment, and software. If
multiple monitors are required, specialized video cards are
necessary when building an audio or video workstation.
3.3 Virtualization Workstations
3.3.1 There is another type of virtualization called Virtual Desktop Infrastructure (VDI). VDI
allows users to log in to a server to access their own virtual computers.Low-powered
devices, known as thin clients, use a server that is much more powerful to perform difficult
calculations. A thin client meets the minimum requirements for running windows and runs
basic applications from the server.These are some other functions of virtual computing:
220.127.116.11 Use other operating systems on one computer, such as Linux or Mac OS X.
18.104.22.168 Browse the Internet without harmful software
hurting your main installation.
22.214.171.124 Test software or software upgrades in an environment that
does not hurt your current operating system environment.
126.96.36.199 Run old applications that are not compatible with modern operating systems.
188.8.131.52 Virtual computing requires more powerful hardware configurations
because each installation needs its own resources.This is some of the
hardware required to run virtual computers:
184.108.40.206.1 Maximum RAM - You need enough RAM to meet the requirements of
each virtual environment and the host computer. A standard installation
using only a few virtual machines might require as little as 64 MB of
RAM to support a modern operating system such as Windows XP. With
multiple users, supporting many virtual computers for each user, you
might need to install as much as 64 GB of RAM or more.
220.127.116.11.2 CPU cores - Although a single core CPU can perform virtual computing, a
CPU with additional cores increases speed and responsiveness when
hosting multiple users and virtual machines. Some VDI installations use
computers that have multiple CPUs that have multiple cores.