CompTIA A+ 220-801 exam. Intro to computer components.

There are many different pieces of hardware used to make up a computer. All of this hardware is unique in what it offers for functionality. In this article you will learn how to identify all of the ports, sockets, chipsets, connectors & hardware used to make up a computer.

Tower Computer Case
Tower Computer Case – Image credit Wikipedia

To start us off, one of the most important components of the computer is the computer caseThe computer case is also known as the chassis. The case holds and protects all of the computers essential components; such as the power supply, motherboard, hard disk drives, solid state drives, optical drives, RAM (random access memory), expansion cards and other drives. There are many different sizes shapes and colors of computer cases.  Some that sit upright are called a tower case while others that lay flat are called a desktop case. Some computer cases have the display built in, these are called all in one computers. Mobile cases are used for tablets and laptops.

When looking at a computer case, you will see numerous ports. These ports are for all types of connections including video, sound, peripheral, data transfer and network connectivity.

Ports commonly found on a computer include:

  • VGA (Video Graphics Array)
  • DVI (Digital Video Interface)
  • HDMI (High-Definition Multimedia Interface)
  • DisplayPort
  • Thunderbolt
  • RJ-45 or Ethernet
  • S/PDIF (Sony-Philips Digital Interface)
  • audio ports

  • USB (Universal Serial Bus)
  • FireWire, eSATA (external SATA)
  • S-Video
  • PS/2,
  • serial
  • parallel
  • modem

VGA port
VGA port – Image credit Wikipedia

The VGA (Video Graphics Array) port is also called a DB-15 port.  This is a type of analog video port used for a computers display. The display is also called a monitor. This port is quickly being replaced by digital ports such as the DVI and HDMI ports. Digital offers a better quality high definition video. While still commonly available, the VGA port is mostly found on older monitors.

DVI port
DVI port – Image credit Wikipedia

The DVI (Digital Video Interface) port has the ability to transmit video to either a digital or analog display. This is helpful if you have a newer computer or port available but a display that only supports VGA. Adapters are available to make the transition.

HDMI – Image credit Wikipedia

The HDMI (High-Definition Multimedia Interface) port supports both audio and video. This port is often used by modern flat screen TV’s and stereo equipment. Today, the HDMI port is also commonly available to connect computers to digital displays with built in audio. This type of port previously only supported a digital transmission but there are now HDMI to VGA adapters available. These are sometimes found with a split off audio cable that can be attached to an audio port and a VGA cable for connecting to analog monitors.

Mini DisplayPort
Mini DisplayPort – Image credit Wikipedia

A DisplayPort also transmits digital video and audio and is beginning to replace VGA and DVI ports. There are also a variety of adapters available for this port. These adapters allow you to connect your VGA or HDMI components to the DisplayPort.

Thunderbolt Port
Thunderbolt Port – Image credit Wikipedia

The Thunderbolt port has the ability to transmit data, audio & video over the same cable. Thunderbolt transfers data at an impressive 10 Gbps. This port is the same size and shape of the DisplayPort and is compatible with DisplayPort devises. There are also a number of adapters available for this port. The Thunderbolt port was developed by Intel and until recently was only available on Macintosh computers.

Rj-45 Ethernet port
Rj-45 port – Image credit Wikipedia

The RJ-45 or Ethernet port is used for wired network connections. This port is used by network cables. These ports transfer data at 100 megabits per second (Mbps), and Gigabit Ethernet transfers data at 1 gigabit per second (Gbps), which is 1,000 Mbps. A gigabit network adapter, switch and router will keep your network speeds at the top. This keeps all computers on a LAN (local area network) communicating it the highest levels.

S/pdif optical digital audio port
S/pdif optical digital audio port – Image credit Wikipedia

S/PDIF (Sony-Philips Digital Interface) optical digital ports are used for audio transmission. This type of port is commonly used to connect your computer to a home theater sound system. This offers the highest quality audio signal.

Computer audio ports
Computer audio ports – Image credit Ryan Franklin – Flickr

The audio ports are round and color coded. There are usually between 3 and 6 of these ports located on a computer. There is usually an audio in for the microphone and an audio out for your speakers and headphones. Sometimes there are extra ports for surround speakers and center speakers.

USB port
USB port – Image credit Wikipedia

USB (Universal Serial Bus) ports are used for multiple devises. These devises include the keyboard, mouse, printer, scanner, external hard drives, flash drives, or web cams.  These ports have gone through some upgrades over the past years as well. USB 1.0 was the original with a transfer speed maxing out around 12 Mbit/s. USB 2.0 transfer speeds were greatly improved and were available at up to 280 Mbit/s. Super Speed USB 3.0 transfer speeds top them all at a whopping 5 Gbps.

FireWire ports
FireWire IEEE1394 ports – Image credit Wikipedia

FireWire ports are also called IEEE1394 ports and were originally developed by Apple.  Today, these ports are most commonly used for multimedia devices. Apple has now stopped using this port and replaced it with the faster and more dynamic Thunderbolt port.

eSATA port
eSATA port – Image credit Wikipedia

eSATA (external SATA) ports are used by external hard drives using the eSATA interface. The eSATA interface is faster than USB 2.0 and for years was considered a professionals choice over USB. Today, USB 3.0 and Thunderbolt are the ports of choice for many professionals.

P/S2 ports
P/S2 ports – Image credit Pixabay

The PS/2 port types were also called a mini-DIN port. Theses round 6-pin ports are color coded green or purple for use with either a mouse or keyboard.  While they look alike, they are not interchangeable. The green port is used for a mouse and the purple port is used for a keyboard. Today these ports have been replaced by USB and are not commonly used.

Serial port
Serial port – Image credit Wikipedia

The Serial port is a 9-pin male port usually only found on older computers. Today, for obscure applications, when a serial port is needed it usually has to be added by way of expansion card. This port is also called a DB9 port and has now been replaced by USB.

Parallel computer printer port
Parallel computer printer port – Image credit Wikipedia

The parallel port is also an older technology. This type of port is a 25-pin female port used by legacy printers. This is another port that has been replaced by the USB port.

Modem port
Modem port – Image credit Wikipedia

The modem port is a legacy item and not commonly found on computers anymore. This port was used to connect a phone line to a computer for a dial up Internet connection. This type of port has been replaced by the RJ-45 port.

The motherboard is the largest and main circuit board inside of a computer.  This board is also known as the system board, main board, mobo or PCB (printed circuit board).  The mother board is the most important piece of computer hardware because it is what connects all of the other components that make up a computer.

A typical motherboard has the following sockets, ports, headers, connectors & chipsets:

  • RAM slots
  • CPU socket
  • Power connectors
  • BIOS
  • CMOS battery
  • USB slots

  • Northbridge
  • Southbridge
  • Expansion slots
  • Chipsets
  • Integrated peripheral ports and connections

Motherboard component Identification
ATX Motherboard component Identification

The mother board comes in various sizes, shapes and colors and has numerous components connected to it.

Motherboard Form Factors. A motherboard is classified by its form factor.  There are few different form factors available.  Some of the most common form factors are the ATX, micro ATX, and ITX. The most common though, is the ATX form factor. When choosing a motherboard for a custom computer build, be sure to select a matching case.

Motherboard Form Factor Comparison
Form Factor Comparison – Image credit Wikipedia

ATX (Advanced Technology Extended). On the ATX motherboard, the processor and memory slots are at a right angle to the expansion slots.  This layout puts the RAM and processor in line with the power supply fan which allows the processor to run cooler. This arrangement also allows for the installation of full length expansion cards.

Micro ATX. The micro ATX form factor is designed to work in standard ATX cases and smaller micro ATX cases. The smaller motherboard and case combo allow you to save some room but with that you lose expansion capacity.  On a micro ATX motherboard there are generally less RAM slots, expansion card slots, USB headers, SATA connectors & integrated components.

ITX. The ITX form factor is actually a whole family of form factors.  These include Mini-ITX (170×170 mm), Nano-ITX (120×120 mm), Pico-ITX (100×72 mm), & Mobile-ITX (60 x 60 mm).  These smaller motherboards have four mounting holes and one expansion slot.  These system boards are generally used for home theater systems.

Components attached the the motherboard.

AMD Phenom II X4 840 CPU
AMD Phenom II X4 840 CPU – Image credit Wikipedia

The CPU (central processing unit) is also called the processor or microprocessor.  This component does the largest amount of data processing for the entire computer system. Because of this, the CPU generates a lot of heat. To keep the CPU cool a processor cooler is needed. A processor cooler is a heat sink with a fan attached to it. This ensemble is placed over the top of the CPU. The heat sink has numerous metal fins that draw the heat away from the microprocessor. Heat sinks are also found on video cards and other computer components that require cooling.

High Performance RAM Random Access Memory
RAM (Random Access Memory) – Image credit Wikipedia

RAM (random access memory) is inserted into memory modules located on the motherboard. These memory modules are call DIMM (dual inline memory module) slots. RAM is a form of temporary storage used for data and instructions that are being processed by the processor. Many video cards also contain embedded dedicated RAM for video and graphics memory.

Soundblaster expansion card
Soundblaster expansion card – Image credit Wikipedia

Expansion cards inserted into a motherboards expansion slots provide a computer with extra ports.  These extra ports can host numerous port types including VGA, DVI, USB, HDMI, eSATA, or Network.  Expansion cards are also called adapter cards. Today, much of the time we find that all of the needed ports are attached directly to the board. These are call onboard ports. Onboard ports allow us to get away with out using expansion cards.

Optical drive
Optical drive – Image credit Wikipedia
Hard Drive (HDD)
Hard Drive (HDD) – Image credit Wikipedia

Hard drives, solid state drives, optical drives & other types of drives are also connected to the motherboard. Hard disk drives (HDD) and solid state drives (SSD) are permanent storage devices used to store data and programs. The operating system is usually the first bit of data installed on a HDD or SSD. Hard drives and SSD’s are located at the front of the computer, stacked into drive bays. Other types of drives you may find attached to the mother board are floppy disk drives & tape drives. Each drive attached to the motherboard requires a power cable from the power supply and a data cable.

SATA (serial ATA) and PATA (parallel ATA 40-pin) are the 2 types of data cables used for hard drives, solid state drives & optical drives. SATA is the newer faster interface and PATA is the older and slower interface. Today SATA is the most commonly used type of data cable but PATA is still found in some legacy systems that you may encounter.

The Floppy drive cable (34-pin) looks a lot like the PATA cable but with 6 less pins.

Solid-State Drive
Solid State Drive (SSD) – Image credit Wikipedia
SATA cable
SATA cable
PATA cable
PATA cable – Image credit Wikipedia

Power Supply (PSU)
Power Supply (PSU) – Image credit Wikipedia

A power supply or PSU (power supply unit) is a box that sits inside the computer case. The power supply is usually located at the top and back side of a computer case.  The power supply converts powerful AC current into usable DC current. Many power supplies have a dual-voltage switch on the back next to where the IEC power cable plugs into the PSU.  This switch allows you to switch the input voltage from 115 V to 220 V depending on where you live.  The power supply has an assortment of power cables with many different types of adapters used to connect to all of the components inside

The power supply has an array of power connectors:

  • 4-pin Molex
  • 15-pin SATA
  • 20-pin P1
  • 20+4 pin P1
  • 24-pin P1
  • 4-pin auxiliary

  • 8-pin auxiliary
  • 4-pin Berg
  • 6-pin PCIe
  • 6+2 pin PCIe
  • 8-pin PCIe

4-pin Molex power supply connector
4-pin Molex power supply connector – Image credit Wikipedia

The 4-pin Molex power connector is used to connect power to a variety of components. Hardware items that use this connector include SATA drives, PATA drives some case fans. SATA drives do have a 15-pin SATA power connector but some have an additional 4-pin Molex connection. This is helpful if you are out of SATA connectors. There are also adapters available that will convert the 4-pin Molex to SATA or other if needed.

15-pin SATA power supply connector
15-pin SATA power supply connector – Image credit Wikipedia

The 15-pin SATA power connector is used for SATA hard drives, optical drives and solid state drives. In some cases you will need to attach a SATA connector to an expansion card to provide needed power.

20-pin P1 power supply connector
20-pin P1 power supply connector – Image credit Wikipedia

The 20-pin P1 power connector is the main motherboard power connector used on older ATX motherboards. Today, the 24-pin power connector is used as the main power connector for motherboards.

20+4 pin power supply connector
20+4 pin power supply connector – Image credit Wikipedia

The 20+4 pin P1 power connector is a 20-pin power connector with an additional 4-pin connector attached. This allows the power supply to be used on older and newer motherboards.

24-pin power supply connector
24-pin power supply connector – Image credit Wikipedia

The 24-pin P1 power connector is the primary power connector for todays motherboards.

4-pin auxiliary power connector
4-pin auxiliary power connector – Image credit Wikipedia

The 4-pin auxiliary power connector is used for an extra 12 volts of power needed by the CPU.

8-pin auxiliary power supply connector
8-pin auxiliary power supply connector

The 8-pin auxiliary power connector is also referred to as the EPS12V cable. Today, many CPU’s need more than power than the 12 volts of power provided by the 4-pin power connector.  Depending on the power supply, this cable may provide one 12 volt rail of power over all 8 pins or 2 x 12 volt rails of power over 4-pins apiece. Keep that in mind when shopping for a power supply.

berg power supply connnector
berg power supply connnector – Image credit WIkipedia

The 4-pin Berg power connector or P7, is used to supply power to a floppy disk drive. Today, this cable is mostly unused. A relic provided just in case you need to connect a floppy disk drive.

6-pin PCIe power supply connector
6-pin PCIe power supply connector

The 6-pin PCIe power connector is used to supply power to expansion cards when needed. Often times this is used for high-end video cards with the version 1 standard.

6+2 pin PCIe power supply connector
6+2 pin PCIe power supply connector

The 6+2 pin PCIe power connector is used to provide an extra 12 volts of power to expansion cards. This is used by high-end video cards that are using a PCIe x 16 card slot. This connector gives you the option of either a 6-pin or 8-pin connector to suit your specific video cards needs.

8-pin PCIe power supply connector
8-pin PCIe power supply connector

The 8-pin PCIe power connector is also used to supply power to expansion cards when needed. This power supply connector is used for high-end video cards that used the version 2 standard.




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