Bus Type Monitor Interface Processing Capabilities Multi-GPU Memory Display Quality HDCP support TV input and output HDMI audio DirectX/OpenGL
Video cards must be compatible with the buses or slots on the motherboard. Common slot types used by video cards are: ◦ Current video cards typically use AGP and PCI express slots. ◦ Video cards in PCIe slots usually require 16x slots. AGP video cards use either 4x or 8x slots. ◦ Older cards used PCI and VESA slots. Some motherboards include a built-in video card integrated on the Northbridge chip. This video card is actually part of one of the buses on the system (PCIe, AGP, or PCI).
The video card includes a connector for attaching the monitor. Choose the video card with the connector(s) you need ◦ VGA ◦ DVI ◦ HDMI ◦ Etc… You can use special conversion plugs to convert from one type of connector to another Many video cards come with HDMI connectors for connecting to a TV or a monitor. If you purchase a video card with duel heads, you can use duel monitors
Video cards include a processor (called a graphics processing unit or GPU) that takes over video rendering from the CPU, thereby increasing video performance. ◦ When selecting a video card, you have a wide choice of video processors. Different processors might improve performance. ◦ The use of this video processor is often referred to as video hardware acceleration. ◦ Typically, settings in the operating system control how much video processing is offloaded to the video card. ◦ Video cards also have a clock speed. Higher speeds typically mean better performance.
For increased performance, especially in games, you can install multiple video cards and link those cards together so that multiple GPUs draw a single screen. ◦ Scalable Link Interface (SLI) from nForce and CrossFire from ATI are two different methods for linking video cards. ◦ Cards are linked using a special bridge clip or through software (depending on the implementation). ◦ The motherboard and the video cards must each support the selected method (either SLI or CrossFire). The motherboard must have multiple 16x PCIe slots. ◦ In most cases you will need to install identical video cards, or at least video cards with very similar specifications.
Video cards have built-in memory. The amount of memory on the card effects performance as well as other characteristics of the display. ◦ The amount of memory ranges from 32 MB up to 2 GB (or more). ◦ Onboard video cards (integrated on the motherboard) use a portion of the system memory for video processing. ◦ Newer video cards will use the following types of memory: DDR, DDR2, and DDR3 memory are similar to system memory. This type of memory is cheaper and provides less performance features than using special graphics memory. GDDR2, GDDR3, and GDDR5 are DDR memory designed specifically for graphics.
HDCP is a method for copy-protecting digital media. The purpose of HDCP is to prevent the interception and copying of protected data streams as they are sent from a playback device (such as a DVD player) to a display device (such as an HD TV). ◦ When playing protected content from a PC, the DVD player, video card, and monitor (or TV) must all support HDCP. ◦ If you plan on watching protected content on your PC, or playing content from your PC to an external TV, make sure the video card supports HDCP.
Some video cards include features that allow them to receive video signals and output them to a TV source. You can display the computer screen on a TV using the following methods: ◦ Analog TVs use an S-video port for video input. ◦ Digital TVs use the HDMI port for input. ◦ Many newer TVs also include a DVI input, allowing you to connect to the DVI port on your computer. ◦ You can also use an HDMI converter to convert a DVI connector to an HDMI connector. A TV tuner allows your video card to accept a cable TV input and change channels from within the computer. TV tuners can process one or more of the following signals: ◦ NTSC, PAL, and SECAM are analog TV signal standards. NTSC was used in North America but is being phased out. ◦ ATSC signals are digital TV signals. When purchasing a new TV tuner, make sure it supports ATSC. Most TV tuners use an S-video, F-type, or RCA composite port for video input.
HDMI used in home theater systems have audio integrated with the video signal. If you connect your video card to a monitor or an HD TV using the HDMI port, only video content will be carried on the HDMI cable. Some video cards allow you to include audio with the video signal using one of the following methods: ◦ With audio pass-through, an audio output cable is connected to the video card. The video card combines the audio signal with the video signal for HDMI output. This option is often called HDTV out. ◦ A graphics card with an onboard audio processor can decode and process audio and send it out the HDMI port. This option is often referred to as onboard sound.
The quality of images and animations are determined by the following characteristics of display. The capability of your display depends on both the video card and the monitor support. -The resolution is the number of pixels displayed on screen. A higher resolution means that more information can be shown on the screen at a time. Modern standards range from 1024 (horizontal) x 756 (vertical) to 2048 x 1536 or even higher. -The color depth is the number of different colors that can be displayed on the screen at a time. Color depth is expressed in bits (a higher bit count increases the number of colors that can be displayed). Common bit depths include: -8-bit (256 possible colors) -16-bit, also called high color (65,536 possible colors) -24-bit, also called true color (16.7 million possible colors) -32-bit, also called true color (16.7 million possible colors and alpha channel) The refresh rate is the number of times the entire screen repaints per second. Refresh rates are measured in hertz. A refresh rate of 70 Hz or lower may cause eye fatigue. A desirable range of refresh rate is 75 Hz to 85 Hz. The refresh rate you use is dependent upon the rate supported by the card as well as the monitor.
DirectX is a set of Microsoft API (Application Program Interface) that improves graphic, animation and multimedia. DirectX includes multiple components targeted to a different aspect of multimedia. For example, Direct3D is the 3D rendering component of DirectX. Applications (typically games) are written using features included in specific DirectX versions. To view content written to a specific DirectX version, your video card must also support that (or a higher) version. OpenGL is an alternative standard to DirectX that is used by some applications. Video cards support both DirectX and OpenGL.
Video cards must be compatible with the buses or slots on the motherboard. Common slot types used by video cards are: Current video cards typically use AGP and PCI express slots. Video cards in PCIe slots usually require 16x slots. AGP video cards use either 4x or 8x Select the video card based on the graphics processor type and speed, the amount and type of video memory, as well as the supported resolution and color depth. Many newer PCI Express cards require a special 6-pin or 8-pin power connector. Be sure to connect the power after inserting the card in the system and prior to turning the system on. If the motherboard has onboard video, disable the onboard video in the BIOS when installing a card in the bus slot.
A cathode ray tube monitor works by illuminating millions of tiny red, blue and green phosphor dots with a beam of electrons A cathode ray tube behind the monitor's screen contains a filament that's held in a vacuum While it is possible for a CRT monitor to have a digital connection, virtually all CRT monitors connect to the video card using a DB-15 (also called a D-sub) connector.
LCDs are flat panels that use a liquid crystal material and transistors to display images. TFT (thin film transistor) and active matrix are additional terms that are often used to describe LCD monitors.
Display Characteristics ◦ Contrast ratio - refers to the difference in light intensity between the brightest white and the darkest black. ◦ Response time - indicates how quickly a pixel can go from black, to white, and back to black. Indicated in milliseconds ◦ Pixel pitch - the distance between pixels. A lower number means a sharper image and possibly higher resolutions.
Display Types Twisted Nematic Panels - most common type used in computer monitors, especially in smaller sizes. TN panels have very good response times (2ms to 5ms), so are well-suited for games with a lot of motion. Vertical Alignment Panels offer the best contrast ratios of the display types, and are well suited for movies that require good contrast. In Plane Switching panels have the best color reproduction quality and viewing angles of the display types, and are well suited for graphic design where full and accurate color representation is required.
An LED (Light-Emitting Diode) based monitor is a special type of LCD monitor. It still uses a liquid crystal display to create images on the screen. However, it uses a different type of backlight than that used in a standard LCD. Traditional LCD monitors use cold cathode florescent (CCFL) tubes to illuminate the display. LED monitors replace the CCFL tubes with LED backlight technology.LED monitors can display more colors more accurately than standard LCD monitors. LED monitors can be manufactured using smaller, thinner dimensions. LEDs use DC power, eliminating the need for an inverter. LED monitors typically consume much less electricity than standard LCDs. LED backlights don't contain mercury, as CCFLs do.
Plasma monitors function using a completely different technology as compared to LCD and LED monitors. Plasma displays utilize small cells that contain electrically-charged ionized gases. A plasma panel is made up of millions of these cells sandwiched between two panels of glass. When electrical current is applied to a plasma cell, the gas within the cell forms a plasma and emits a photon of light Each photon strikes a phosphor painted on the inside of the cell, allowing different colors to be displayed. Each pixel in a plasma display is made up of three cells; red, green, and blue.
Picture Quality ◦ For normal computing purposes, both provide a sharp, clear display. ◦ Plasmas typically shine when watching Blu-Ray movies or playing high definition games. They tend to have less picture lag and sharper color resolution than LCD displays.
Lifespan ◦ LCD monitors tend to be rated for 60,000 + hours of use ◦ Plasma monitors are usually rated between 20,000 – 30,000 hours Pixel Levels ◦ LCD screens typically have more pixels per square inch than plasmas, making them more ideal for working with complex spreadsheet programs or editing software. Power Usage ◦ LCD displays tend to use much less power than plasma displays, due to the fact that plasma screens have self lighting pixels
More than one monitor can be attached to the same device. Each display can operate in two different configurations. ◦ Extend – extends your desktop across both monitors. Useful for creating more desktop space ◦ Mirror – when both monitors are showing the same screen. Useful for giving presentations
VGA cable ◦ The D-sub connector, sometimes called a VGA connector, uses a DB-15 connector with three rows of pins. The D-sub connector on a video card provides analog output. You can connect the following monitors to a video card with a D- sub connector. Typically used with an analog CRT monitor, but some LCD monitors also have analog ports as well.
A DVI-D (digital video-digital) connection on a video card provides digital output. DVI-D connections are rated as either single link or dual link: ◦ Single link connectors have 3 rows of 6 pins with one additional larger horizontal pin. Single link can support 60 Hz up to 1920x1080 resolution. ◦ Dual link connectors have 3 rows of 8 pins plus the horizontal pin (often called a 25-pin, 24+1-pin, or 24-pin connector). Dual link can support 60 Hz up to 2048x1536 resolution. ◦ Dual link allows for longer cable lengths and a higher video resolution. When choosing a video card, choose a card that supports dual link whenever possible. ◦ You can only connect a digital monitor to a DVI-D connector.
High-Definition Multimedia Interface (HDMI) is a digital video and audio connector used for high-definition digital audio and video. HDMI combines the audio and video signals onto a single cable. You might use HDMI connectors in the following configurations: ◦ You can use a DVI-to-HDMI cable to connect the DVI-D output from a video card to a monitor or an HDTV device that has an HDMI connector. However, this configuration only supplies video, and not audio, to the display device. ◦ You can purchase a video card with an HDMI connector. Many of these video cards have an audio input port that accepts digital audio into the video card where the audio signals are combined with the video signals and sent out the HDMI port. In this configuration, the video card does not process the audio, but simply passes it through the video card from the external source and onto the HDMI output.