CompTIA A+ Exam Prep: Adapter Cards and Their Functions

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There are many types of adapter cards that go into a computer system. Today we'll go over each type of adapter card as required by the 2009 CompTIA A+ exam (click here for the latest CompTIA A+ training course).

Objective 1.9 of the A+ 2009 exam goes over the types and functions of adapter cards, including:

  • Video Cards (PCI, PCIe, and AGP)
  • Multimedia Cards (Sound Cards, TV Tuner Cards, and Capture Cards)
  • I/O Cards (SCSI, Serial, USB, and Parallel)
  • Communications Cards (NICs and Modems)

Today we'll go over each of these types of adapter cards and their functions to help you prepare for the 2009 A+ exam.

Video Cards

The first, and arguably one of the most important, types of adapter cards are video cards. Also known as graphics accelerators, graphics processors, display cards, or graphics cards; video cards do the heavy lifting in allowing you see and interface with what you are doing in your computer. Video cards generate the graphics to be shown and send the finished signal out to your monitor, screen or projector.

The first connector type listed on the exam is a PCI connector type. While PCI type video cards weren't the first type out, there were definitely a standard and milestone in connections. PCI video cards replaced the EISA, ISA, MCA and VESA buses from 1993 onwards. PCI made it easier to use video cards as there were no manual adjustments, such as jumpers, that needed to be made. PCI slots allowed the video card to connect dynamically between devices. A PCI slot is a 32 to 64-bit bus set at 33MHz to 100MHz. PCI buses can handle up to 800MB/s of bandwidth.

[caption id="attachment_15843" align="aligncenter" width="500"]Example of a Video Card Example of a Video Card. Photo by qwikrex.[/caption]

Accelerated Graphics Ports (AGPs) were first used in 1997 and are arguably the most popular and long running graphics port up until about 2006 when PCI Express reached double the data-transfer rate of AGP. AGP Graphics cards come in four flavors. 1x, 2x, 4x, and 8x. While all are 32-bits and rated at 66MHz, they are separated by their bandwidth ability. Starting at 264MB/s for 1x and going up to 528MB/s for 2x, 1000MB/s for 4x and 2000MB/s for 8x.

PCI Express (PCIe 1.0) cards have been standard since about 2006 and offer tremendous amounts of bandwidth and a much higher rate of speed. As of 2009, they have completely replaced AGP cards, as proved by the fact that the world's two largest video card companies, ATI and nVidia, now create PCIe cards exclusively. While the highest clock rate seen before was up to 100MHz with PCI, PCIe is rated at 2,500-5,000MHz. PCIe video cards are the first to separate themselves from the standard Parallel interface, moving on to the Serial interface. PCIe also comes in four flavors differentiated by their bandwidth; PCIe x1 can support up to 500MB/s, PCIe x4 can support up to 1,000MB/s, PCIe x8 can support up to 4,000MB/s, and PCIe x16 can support up to 8,000MB/s.

While PCIe x16 2.0 is not on the 2009 A+ Bridge Exam, I feel it is important to cover as it is the latest technology set to replace PCI Express 1.0. PCI Express 3.0 is still in the works. PCIe x16 2.0 runs at up to 10,000MHz and supports up to 16,000MB/s of bandwidth. These specifications, which double todays high-end standard, set it apart from the rest in terms of high end computing, especially in terms of gaming, HD, and 3D development video cards.

Multimedia Cards

Aside from video cards, there are many other types of multimedia cards available and commonly used in computer systems.

One of the most common cards would have to be the sound card. Sound cards do exactly what you would expect; they generate sound signals to be sent to your speakers and sound systems. In most cases, they are also usually where you would find a microphone or input jack for recording. Sound cards are increasing in importance as new technologies like HD audio discs and Blu-Ray discs allow for high definition and multi-channel audio.

Standard or built in sound cards are usually not powerful enough to process the high end sound files, cannot send audio to more than two channels, and produce lower quality results. In the past, high end sound cards were generally only used in studio recording environments. Today, upgrading your sound card allows the average consumer to listen to high quality audio in music, games, and movies, and allows your computer system to be connected to surround sound systems taking advantage of all available sound channels.

[caption id="attachment_15846" align="aligncenter" width="500"]8 Channel PCI sound card 8 Channel PCI Sound Card. Photo by whiskymac.[/caption]

TV tuner cards are another type of multimedia adapter card. TV tuners are used to process coaxial and other types of video inputs to display on your computer system. TV tuners are able to differentiate different channels much like your TV does, essentially turning your computer system into a television and digital video recorder. Many TV tuners also function as AM/FM radio tuners, allowing you to listen to your favorite local radio stations right on your computer system.

Capture cards are much like TV tuners, except rather than focusing on its ability to tune into different channels of video, capture cards focus on pulling one stream of high quality video from an external source, such as a video camera. Capture cards are generally used to capture video inputs from digital sources like Firewire, and analog inputs like RCA and S-Video. While some capture cards do allow you to capture coaxial TV inputs as well, they are generally only used for single video input sources.

[caption id="attachment_15847" align="aligncenter" width="500"]Example of a Capture Card Example of a Capture Card. Photo by asvravi.[/caption]

I/O Cards

Input/Output cards, also known as expansion cards, are simply cards that add extra functionality to your current motherboard. For example, if your motherboard does not have any USB 2.0 slots, you can connect a USB 2.0 I/O card into your PCI slot to add a few USB 2.0 slots to the back of your computer. There are four types of I/O cards that are mentioned in the 2009 A+ Bridge Exam, but they all essentially do the same thing.

[caption id="attachment_15848" align="aligncenter" width="615"]Example of a USB Card Example of a USB Card. Photo by Sam_catch.[/caption]

The first is a SCSI (commonly pronounced Scuzzy) expansion card. A SCSI expansion card allows you to connect internal and external SCSI hard drives to your computer system. Serial cards are also covered, since serial ports have been removed from most newer computer systems, serial expansion cards (usually connected through PCI) are an alternative way to connect serial devices to your computer system.

As noted above, USB expansion cards either add USB functionality, or add extra ports to your computer. Finally, parallel expansion cards add parallel ports to your computer system. Parallel ports were commonly used as printer ports, however, with USB and Ethernet replacing the printing interface, parallel ports are now mostly used for custom-made peripherals due to it's architectural simplicity.


There are two types of communications cards used in computer systems today: Network Interface Cards (NIC) and Modem Cards. NIC cards are generally used to give you access to wired Ethernet networks between 10Mbit and 1Gbit connection speeds. Some NIC cards also include wireless networking as well. Modems are used for dial-up access to the internet, phone systems, and can also function as a FAX machine would.


While these are definitely not the only types of adapter cards available today, they are the most common and are required knowledge on the 2009 A+ Bridge Exam. I hope this exam preparation has helped you refresh your memory on some of the requirements. Best of luck on your exam!

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Mike Rodriguez

Mike Rodriguez is a computer technician with over 8 years of experience in the IT field. He has completed training in CompTIA A+, Network+, Computer Business Applications (Microsoft Specialist), Web Page Design and Graphic Design, and is working on completing his CompTIA A+ and CCNA certifications. Mike has experience working as a computer technician for two local school districts, as well as freelance computer repair work with, which Mike owns. Music is another one of Mike's callings. Using his technical experience, Mike promotes local musicians in Salinas California through his website where local musicians and businesses can gain promotion to a worldwide audience.