Video card
Encyclopedia
A video card, Graphics Card, or Graphics adapter is an expansion card
which generates output images to a display. Most video cards offer various functions such as accelerated rendering of 3D
scenes and 2D graphics
, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors (multi-monitor). Other modern high performance video cards are used for more graphically demanding purposes, such as PC games.
Video hardware is often integrated into the motherboard
, however all modern motherboards provide expansion ports to which a video card can be attached. In this configuration it is sometimes referred to as a video controller or graphics controller. Modern low-end to mid-range motherboards often include a graphics chipset manufactured by the developer of the northbridge
(i.e. an nForce
chipset with Nvidia
graphics or an Intel chipset with Intel graphics) on the motherboard. This graphics chip usually has a small quantity of embedded memory and takes some of the system's main RAM, reducing the total RAM available. This is usually called integrated graphics or on-board graphics, and is low-performance and undesirable for those wishing to run 3D applications.
A dedicated graphics card on the other hand has its own RAM and Processor specifically for processing video images, and thus offloads this work from the CPU and system RAM.
Almost all of these motherboards allow the disabling of the integrated graphics chip in BIOS
, and have an AGP, PCI
, or PCI Express
slot for adding a higher-performance graphics card in place of the integrated graphics.
on which the components are mounted. These include:
s), which translate a 3D image characterized by vertices and lines into a 2D image formed by pixel
s.
Modern GPUs are massively parallel, and fully programmable. Their computing power in orders of magnitude are higher than that of CPUs. As consequence, they challenge CPUs in high performance computing, and push leading manufacturers on processors.
or firmware
contains the basic program, which is usually hidden, that governs the video card's operations and provides the instructions that allow the computer and software to interact with the card. It may contain information on the memory timing, operating speeds and voltages of the graphics processor, RAM, and other information. It is sometimes possible to change the BIOS (e.g. to enable factory-locked settings for higher performance), although this is typically only done by video card overclockers and has the potential to irreversibly damage the card.
The memory capacity of most modern video cards ranges from 128 MB to 8 GB. Since video memory needs to be accessed by the GPU and the display circuitry, it often uses special high-speed or multi-port memory, such as VRAM, WRAM, SGRAM, etc. Around 2003, the video memory was typically based on DDR
technology. During and after that year, manufacturers moved towards DDR2
, GDDR3
, GDDR4
and GDDR5
. The effective memory clock rate in modern cards is generally between 400 MHz and 3.8 GHz.
Video memory may be used for storing other data as well as the screen image, such as the Z-buffer
, which manages the depth coordinates in 3D graphics
, textures, vertex buffers, and compiled shader programs.
, or Random Access Memory Digital-to-Analog Converter, converts digital signal
s to analog signal
s for use by a computer display that uses analog inputs such as CRT
displays. The RAMDAC is a kind of RAM chip that regulates the functioning of the graphics card. Depending on the number of bits used and the RAMDAC-data-transfer rate, the converter will be able to support different computer-display refresh rates. With CRT displays, it is best to work over 75 Hz and never under 60 Hz, in order to minimize flicker. (With LCD displays, flicker is not a problem.) Due to the growing popularity of digital computer displays and the integration of the RAMDAC onto the GPU die, it has mostly disappeared as a discrete component. All current LCDs, plasma displays and TVs work in the digital domain and do not require a RAMDAC. There are few remaining legacy LCD and plasma displays that feature analog inputs (VGA
, component, SCART
etc.) only. These require a RAMDAC, but they reconvert the analog signal back to digital before they can display it, with the unavoidable loss of quality stemming from this digital-to-analog-to-digital conversion.
The most common connection systems between the video card and the computer display are:
Analog-based standard adopted in the late 1980s designed for CRT displays, also called VGA connector
. Some problems of this standard are electrical noise
, image distortion and sampling error
evaluating pixels.
Digital-based standard designed for displays such as flat-panel displays (LCD
s, plasma screens, wide high-definition television
displays) and video projectors. In some rare cases high end CRT monitors also use DVI. It avoids image distortion and electrical noise, corresponding each pixel from the computer to a display pixel, using its native resolution
. It is worth to note that most manufacturers include DVI-I connector, allowing(via simple adapter) standard RGB signal output to an old CRT or LCD monitor with VGA input.
Included to allow the connection with television
s, DVD player
s, video recorders
and video game console
s. They often come in two 10-pin mini-DIN connector
variations, and the VIVO splitter cable generally comes with either 4 connectors (S-Video in and out + composite video in and out), or 6 connectors (S-Video in and out + component PB out + component PR out + component Y out [also composite out] + composite in).
An advanced digital audio/video interconnect released in 2003 and is commonly used to connect game consoles and DVD players to a display. HDMI supports copy protection through HDCP
.
An advanced license- and royalty-free digital audio/video interconnect released in 2007. DisplayPort
intends to replace VGA and DVI for connecting a display to a computer.
'
In the attached table is a comparison between a selection of the features of some of those interfaces.
makers have recently moved toward higher efficiency, power demands of GPUs have continued to rise, so the video card may be the biggest electricity user in a computer. Although power supplies are increasing their power too, the bottleneck
is due to the PCI-Express connection, which is limited to supplying 75 Watts.
Modern video cards with a power consumption over 75 Watts usually include a combination of six-pin (75W) or eight-pin (150W) sockets that connect directly to the power supply
Expansion card
The expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.One edge of the expansion card holds the contacts that fit exactly into the slot...
which generates output images to a display. Most video cards offer various functions such as accelerated rendering of 3D
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
scenes and 2D graphics
2D computer graphics
2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors (multi-monitor). Other modern high performance video cards are used for more graphically demanding purposes, such as PC games.
Video hardware is often integrated into the motherboard
Motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
, however all modern motherboards provide expansion ports to which a video card can be attached. In this configuration it is sometimes referred to as a video controller or graphics controller. Modern low-end to mid-range motherboards often include a graphics chipset manufactured by the developer of the northbridge
Northbridge (computing)
The northbridge has historically been one of the two chips in the core logic chipset on a PC motherboard, the other being the southbridge. Increasingly these functions have migrated to the CPU chip itself, beginning with memory and graphics controllers. For Intel Sandy Bridge and AMD Fusion...
(i.e. an nForce
NForce
The nForce is a motherboard chipset created by Nvidia for AMD Athlon and Duron microprocessors. The chipset shipped in 3 varieties; 220, 415, and 420. 220 and 420 are very similar with each having the integrated GPU, but the 220 only has a single channel of memory available whereas 420 has the...
chipset with Nvidia
NVIDIA
Nvidia is an American global technology company based in Santa Clara, California. Nvidia is best known for its graphics processors . Nvidia and chief rival AMD Graphics Techonologies have dominated the high performance GPU market, pushing other manufacturers to smaller, niche roles...
graphics or an Intel chipset with Intel graphics) on the motherboard. This graphics chip usually has a small quantity of embedded memory and takes some of the system's main RAM, reducing the total RAM available. This is usually called integrated graphics or on-board graphics, and is low-performance and undesirable for those wishing to run 3D applications.
A dedicated graphics card on the other hand has its own RAM and Processor specifically for processing video images, and thus offloads this work from the CPU and system RAM.
Almost all of these motherboards allow the disabling of the integrated graphics chip in BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
, and have an AGP, PCI
Peripheral Component Interconnect
Conventional PCI is a computer bus for attaching hardware devices in a computer...
, or PCI Express
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
slot for adding a higher-performance graphics card in place of the integrated graphics.
Components
A modern video card consists of a printed circuit boardPrinted circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
on which the components are mounted. These include:
Graphics Processing Unit
A GPU is a dedicated processor optimized for accelerating graphics. The processor is designed specifically to perform floating-point calculations, which are fundamental to 3D graphics rendering and 2D picture drawing. The main attributes of the GPU are the core clock frequency, which typically ranges from 250 MHz to 4 GHz and the number of pipelines (vertex and fragment shaderShader
In the field of computer graphics, a shader is a computer program that is used primarily to calculate rendering effects on graphics hardware with a high degree of flexibility...
s), which translate a 3D image characterized by vertices and lines into a 2D image formed by pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s.
Modern GPUs are massively parallel, and fully programmable. Their computing power in orders of magnitude are higher than that of CPUs. As consequence, they challenge CPUs in high performance computing, and push leading manufacturers on processors.
Video BIOS
The video BIOSVideo BIOS
Video BIOS is the BIOS of a graphics card in a computer.Much the way the system BIOS provides a set of functions that are used by software programs to access the system hardware, the video BIOS provides a set of video-related functions that are used by programs to access the video hardware...
or firmware
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...
contains the basic program, which is usually hidden, that governs the video card's operations and provides the instructions that allow the computer and software to interact with the card. It may contain information on the memory timing, operating speeds and voltages of the graphics processor, RAM, and other information. It is sometimes possible to change the BIOS (e.g. to enable factory-locked settings for higher performance), although this is typically only done by video card overclockers and has the potential to irreversibly damage the card.
Video memory
| Type | Memory clock rate (MHz) | Bandwidth (GB/s) |
|---|---|---|
| DDR DDR SDRAM Double data rate synchronous dynamic random access memory is a class of memory integrated circuits used in computers. DDR SDRAM has been superseded by DDR2 SDRAM and DDR3 SDRAM, neither of which are either forward or backward compatible with DDR SDRAM, meaning that DDR2 or DDR3 memory modules... |
166 - 950 | 1.2 - 30.4 |
| DDR2 DDR2 SDRAM DDR2 SDRAM is a double data rate synchronous dynamic random-access memory interface. It supersedes the original DDR SDRAM specification and has itself been superseded by DDR3 SDRAM... |
533 - 1000 | 8.5 - 16 |
| GDDR3 GDDR3 Graphics Double Data Rate 3 is a graphics card-specific memory technology, designed by ATI Technologies with the collaboration of JEDEC.It has much the same technological base as DDR2, but the power and heat dispersal requirements have been reduced somewhat, allowing for higher performance memory... |
700 - 2400 | 5.6 - 156.6 |
| GDDR4 GDDR4 GDDR4 SDRAM is a type of graphics card memory specified by the JEDEC Semiconductor Memory Standard. It is a rival medium to Rambus's XDR DRAM... |
2000 - 3600 | 128 - 200 |
| GDDR5 GDDR5 GDDR5 SDRAM is a type of high performance DRAM graphics card memory designed for computer applications requiring high bandwidth... |
900 - 5600 | 130 - 230 |
The memory capacity of most modern video cards ranges from 128 MB to 8 GB. Since video memory needs to be accessed by the GPU and the display circuitry, it often uses special high-speed or multi-port memory, such as VRAM, WRAM, SGRAM, etc. Around 2003, the video memory was typically based on DDR
Double data rate
In computing, a computer bus operating with double data rate transfers data on both the rising and falling edges of the clock signal. This is also known as double pumped, dual-pumped, and double transition....
technology. During and after that year, manufacturers moved towards DDR2
DDR2 SDRAM
DDR2 SDRAM is a double data rate synchronous dynamic random-access memory interface. It supersedes the original DDR SDRAM specification and has itself been superseded by DDR3 SDRAM...
, GDDR3
GDDR3
Graphics Double Data Rate 3 is a graphics card-specific memory technology, designed by ATI Technologies with the collaboration of JEDEC.It has much the same technological base as DDR2, but the power and heat dispersal requirements have been reduced somewhat, allowing for higher performance memory...
, GDDR4
GDDR4
GDDR4 SDRAM is a type of graphics card memory specified by the JEDEC Semiconductor Memory Standard. It is a rival medium to Rambus's XDR DRAM...
and GDDR5
GDDR5
GDDR5 SDRAM is a type of high performance DRAM graphics card memory designed for computer applications requiring high bandwidth...
. The effective memory clock rate in modern cards is generally between 400 MHz and 3.8 GHz.
Video memory may be used for storing other data as well as the screen image, such as the Z-buffer
Z-buffering
In computer graphics, z-buffering is the management of image depth coordinates in three-dimensional graphics, usually done in hardware, sometimes in software. It is one solution to the visibility problem, which is the problem of deciding which elements of a rendered scene are visible, and which...
, which manages the depth coordinates in 3D graphics
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
, textures, vertex buffers, and compiled shader programs.
RAMDAC
The RAMDACRAMDAC
Random Access Memory Digital-to-Analog Converter is a combination of three fast DACs with a small SRAM used in computer graphics display adapters to store the color palette and to generate the analog signals to drive a color monitor...
, or Random Access Memory Digital-to-Analog Converter, converts digital signal
Digital signal
A digital signal is a physical signal that is a representation of a sequence of discrete values , for example of an arbitrary bit stream, or of a digitized analog signal...
s to analog signal
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
s for use by a computer display that uses analog inputs such as CRT
Cathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
displays. The RAMDAC is a kind of RAM chip that regulates the functioning of the graphics card. Depending on the number of bits used and the RAMDAC-data-transfer rate, the converter will be able to support different computer-display refresh rates. With CRT displays, it is best to work over 75 Hz and never under 60 Hz, in order to minimize flicker. (With LCD displays, flicker is not a problem.) Due to the growing popularity of digital computer displays and the integration of the RAMDAC onto the GPU die, it has mostly disappeared as a discrete component. All current LCDs, plasma displays and TVs work in the digital domain and do not require a RAMDAC. There are few remaining legacy LCD and plasma displays that feature analog inputs (VGA
Video Graphics Array
Video Graphics Array refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987, but through its widespread adoption has also come to mean either an analog computer display standard, the 15-pin D-subminiature VGA connector or the 640×480 resolution...
, component, SCART
SCART
SCART is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together...
etc.) only. These require a RAMDAC, but they reconvert the analog signal back to digital before they can display it, with the unavoidable loss of quality stemming from this digital-to-analog-to-digital conversion.
Outputs
Video Graphics Array (VGA) (DB-15)
VGA connector
A Video Graphics Array connector is a three-row 15-pin DE-15 connector. The 15-pin VGA connector is found on many video cards, computer monitors, and some high definition television sets...
. Some problems of this standard are electrical noise
Electromagnetic interference
Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
, image distortion and sampling error
Sampling error
-Random sampling:In statistics, sampling error or estimation error is the error caused by observing a sample instead of the whole population. The sampling error can be found by subtracting the value of a parameter from the value of a statistic...
evaluating pixels.
Digital Visual Interface (DVI)
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
s, plasma screens, wide high-definition television
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...
displays) and video projectors. In some rare cases high end CRT monitors also use DVI. It avoids image distortion and electrical noise, corresponding each pixel from the computer to a display pixel, using its native resolution
Native resolution
The native resolution of a LCD, LCoS or other flat panel display refers to its single fixed resolution. As an LCD display consists of a fixed raster, it cannot change resolution to match the signal being displayed as a CRT monitor can, meaning that optimal display quality can be reached only when...
. It is worth to note that most manufacturers include DVI-I connector, allowing(via simple adapter) standard RGB signal output to an old CRT or LCD monitor with VGA input.
Video In Video Out (VIVO) for S-Video, Composite video and Component video
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
s, DVD player
DVD player
A DVD player is a device that plays discs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. These devices were invented in 1997 and continue to thrive...
s, video recorders
Videocassette recorder
The videocassette recorder , is a type of electro-mechanical device that uses removable videocassettes that contain magnetic tape for recording analog audio and analog video from broadcast television so that the images and sound can be played back at a more convenient time...
and video game console
Video game console
A video game console is an interactive entertainment computer or customized computer system that produces a video display signal which can be used with a display device to display a video game...
s. They often come in two 10-pin mini-DIN connector
Mini-DIN connector
The mini-DIN connectors are a family of multi-pin electrical connectors used in a variety of applications. Mini-DIN is similar to the larger, older DIN connector...
variations, and the VIVO splitter cable generally comes with either 4 connectors (S-Video in and out + composite video in and out), or 6 connectors (S-Video in and out + component PB out + component PR out + component Y out [also composite out] + composite in).
High-Definition Multimedia Interface (HDMI)
High-Bandwidth Digital Content Protection
High-bandwidth Digital Content Protection is a form of digital copy protection developed by Intel Corporation to prevent copying of digital audio and video content as it travels across connections...
.
DisplayPort
DisplayPort
DisplayPort is a digital display interface standard produced by the Video Electronics Standards Association . The specification defines a royalty-free digital interconnect for audio and video. The interface is primarily used to connect a video source to a display device such as a computer monitor...
intends to replace VGA and DVI for connecting a display to a computer.
Other types of connection systems
| Composite video Composite video Composite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal... |
Analog system with lower resolution; it uses the RCA connector RCA connector An RCA connector, sometimes called a phono connector or cinch connector, is a type of electrical connector commonly used to carry audio and video signals... . |
|---|---|
| Component video Component video Component video is a video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video information that is transmitted or stored as three separate signals... |
It has three cables, each with RCA connector (YCBCR YCbCr YCbCr or Y′CbCr, sometimes written or , is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components... for digital component, or YPBPR YPbPr ' is a color space used in video electronics, in particular in reference to component video cables. is the analog version of the YCBCR color space; the two are numerically equivalent, but YPBPR is designed for use in analog systems whereas YCBCR is intended for digital video. cables are also... for analog component); it is used in projectors, DVD players and some televisions. |
 |
|
| DB13W3 DB13W3 DB13W3 is a particular style of D-subminiature connector commonly used as an analog video interface connector that was used primarily on Sun Microsystems, Silicon Graphics and IBM RISC workstations, as well as some displays from Apple Computer, NeXT Computer and Intergraph Corporation... |
An analog standard once used by Sun Microsystems Sun Microsystems Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982... , SGI Silicon Graphics Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark... and IBM IBM International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas... . |
 |
|
| DMS-59 DMS-59 DMS-59 is a 59-pin electrical connector generally used for computer video cards. It provides two DVI or VGA outputs on a single connector. An adapter cable is needed for conversion from DMS-59 to DVI or VGA , and different types of adapter cables exist... |
A connector that provides two DVI Digital Visual Interface The Digital Visual Interface is a video interface standard covering the transmission of video between a source device and a display device. The DVI standard has achieved widespread acceptance in the PC industry, both in desktop PCs and monitors... or VGA Video Graphics Array Video Graphics Array refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987, but through its widespread adoption has also come to mean either an analog computer display standard, the 15-pin D-subminiature VGA connector or the 640×480 resolution... outputs on a single connector. This is a DMS-59 port. |
 |
Motherboard interface
Chronologically, connection systems between video card and motherboard were, mainly:- S-100 busS-100 busThe S-100 bus or Altair bus, IEEE696-1983 , was an early computer bus designed in 1974 as a part of the Altair 8800, generally considered today to be the first personal computer...
: designed in 1974 as a part of the Altair 8800, it was the first industry-standard bus for the microcomputer industry. - ISAIndustry Standard ArchitectureIndustry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
: Introduced in 1981 by IBMIBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
, it became dominant in the marketplace in the 1980s. It was an 8 or 16-bit bus clocked at 8 MHz. - NuBusNuBusNuBus is a 32-bit parallel computer bus, originally developed at MIT as a part of the NuMachine workstation project. The first complete implementation of the NuBus and the NuMachine was done by Western Digital for their NuMachine, and for the Lisp Machines Inc. LMI-Lambda. The NuBus was later...
: Used in Macintosh IIMacintosh IIThe Apple Macintosh II was the first personal computer model of the Macintosh II series in the Apple Macintosh line and the first Macintosh to support a color display.- History :...
, it was a 32-bit bus with an average bandwidth of 10 to 20 MB/s. - MCAMicro Channel architectureMicro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
: Introduced in 1987 by IBM it was a 32-bit bus clocked at 10 MHz. - EISAExtended Industry Standard ArchitectureThe Extended Industry Standard Architecture is a bus standard for IBM PC compatible computers...
: Released in 1988 to compete with IBM's MCA, it was compatible with the earlier ISA bus. It was a 32-bit bus clocked at 8.33 MHz. - VLBVESA Local BusThe VESA Local Bus was mostly used in personal computers. VESA Local Bus worked alongside the ISA bus; it acted as a high-speed conduit for memory-mapped I/O and DMA, while the ISA bus handled interrupts and port-mapped I/O.-Historical overview:In the early 1990s, the I/O bandwidth of...
: An extension of ISA, it was a 32-bit bus clocked at 33 MHz. - PCIPeripheral Component InterconnectConventional PCI is a computer bus for attaching hardware devices in a computer...
: Replaced the EISA, ISA, MCA and VESA buses from 1993 onwards. PCI allowed dynamic connectivity between devices, avoiding the jumpersJumper (computing)In electronics and particularly computing, a jumper is a short length of conductor used to close a break in or bypass part of an electrical circuit...
manual adjustments. It is a 32-bit bus clocked 33 MHz. - UPAUltra Port ArchitectureThe Ultra Port Architecture bus was developed by Sun Microsystems as a high-speed graphics card to CPU interconnect, beginning with the Ultra 1 workstation in 1995.-External links:*...
: An interconnect bus architecture introduced by Sun MicrosystemsSun MicrosystemsSun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
in 1995. It had a 64-bit bus clocked at 67 or 83 MHz. - USB: Although mostly used for miscellaneous devices, such as secondary storage devices and toysUSB toysUSB toys are toys or gadgets which draw their electrical power from the USB or Universal serial bus on a computer. They are also known as "office toys" or "cubicle toys".-Types:There are, broadly, 2 categories for USB toys, useful toys and fun toys...
, USB displays and display adapters exist. - AGPAccelerated Graphics PortThe Accelerated Graphics Port is a high-speed point-to-point channel for attaching a video card to a computer's motherboard, primarily to assist in the acceleration of 3D computer graphics. Since 2004 AGP has been progressively phased out in favor of PCI Express...
: First used in 1997, it is a dedicated-to-graphics bus. It is a 32-bit bus clocked at 66 MHz. - PCI-XPCI-XPCI-X, short for PCI-eXtended, is a computer bus and expansion card standard that enhances the 32-bit PCI Local Bus for higher bandwidth demanded by servers. It is a double-wide version of PCI, running at up to four times the clock speed, but is otherwise similar in electrical implementation and...
: An extension of the PCI bus, it was introduced in 1998. It improves upon PCI by extending the width of bus to 64-bit and the clock frequency to up to 133 MHz. - PCI ExpressPCI ExpressPCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
: Abbreviated PCIe, it is a point to point interface released in 2004. In 2006 provided double the data-transfer rate of AGP. It should not be confused with PCI-XPCI-XPCI-X, short for PCI-eXtended, is a computer bus and expansion card standard that enhances the 32-bit PCI Local Bus for higher bandwidth demanded by servers. It is a double-wide version of PCI, running at up to four times the clock speed, but is otherwise similar in electrical implementation and...
, an enhanced version of the original PCI specification.
In the attached table is a comparison between a selection of the features of some of those interfaces.
| Bus | Width (bits) | Clock rate (MHz) | Bandwidth (MB/s) | Style |
|---|---|---|---|---|
| ISA XT | 8 | 4,77 | 8 | Parallel |
| ISA AT | 16 | 8,33 | 16 | Parallel |
| MCA | 32 | 10 | 20 | Parallel |
| NUBUS | 32 | 10 | 10-40 | Parallel |
| EISA | 32 | 8,33 | 32 | Parallel |
| VESA | 32 | 40 | 160 | Parallel |
| PCI | 32 - 64 | 33 - 100 | 132 - 800 | Parallel |
| AGP 1x | 32 | 66 | 264 | Parallel |
| AGP 2x | 32 | 66 | 528 | Parallel |
| AGP 4x | 32 | 66 | 1000 | Parallel |
| AGP 8x | 32 | 66 | 2000 | Parallel |
| PCIe x1 | 1 | 2500 / 5000 | 250 / 500 | Serial |
| PCIe x4 | 1 × 4 | 2500 / 5000 | 1000 / 2000 | Serial |
| PCIe x8 | 1 × 8 | 2500 / 5000 | 2000 / 4000 | Serial |
| PCIe x16 | 1 × 16 | 2500 / 5000 | 4000 / 8000 | Serial |
| PCIe x16 2.0 | 1 × 16 | 5000 / 10000 | 8000 / 16000 | Serial |
Cooling devices
Video cards may use a lot of electricity, which is converted into heat. If the heat isn't dissipated, the video card could overheat and be damaged. Cooling devices are incorporated to transfer the heat elsewhere. Three types of cooling devices are commonly used on video cards:- Heat sinkHeat sinkA heat sink is a term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or a liquid. Examples of heat sinks are the heat exchangers used in refrigeration and air conditioning systems and the radiator in a car...
: a heat sink is a passive-cooling device. It conducts heat away from the graphics card's core, or memory, by using a heat-conductive metal (most commonly aluminum or copper); sometimes in combination with heat pipes. It uses air (most common), or in extreme cooling situations, water (see water blockWater blockA water block is the watercooling equivalent of a heatsink. It can be used on many different computer components including the central processing unit , GPU, PPU, and Northbridge chipset on the motherboard...
), to remove the heat from the card. When air is used, a fan is often used to increase cooling effectiveness. - Computer fanComputer fanA computer fan is any fan inside, or attached to, a computer case used for cooling purposes, and may refer to fans that draw cooler air into the case from the outside, expel warm air from inside, or move air across a heatsink to cool a particular component...
: an example of an active-cooling part. It is usually used with a heat sink. Due to the moving parts, a fan requires maintenance and possible replacement. The fan speed or actual fan can be changed for more efficient or quieter cooling. - Water blockWater blockA water block is the watercooling equivalent of a heatsink. It can be used on many different computer components including the central processing unit , GPU, PPU, and Northbridge chipset on the motherboard...
: a water block is a heat sink suited to use water instead of air. It is mounted on the graphics processor and has a hollow inside. Water is pumped through the water block, transferring the heat into the water, which is then usually cooled in a radiator. This is the most effective cooling solution without extreme modification.
Power demand
As the processing power of video cards has increased, so has their demand for electrical power. Current high-performance video cards tend to consume a great deal of power. While CPU and power supplyPower supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
makers have recently moved toward higher efficiency, power demands of GPUs have continued to rise, so the video card may be the biggest electricity user in a computer. Although power supplies are increasing their power too, the bottleneck
Bottleneck
A bottleneck is a phenomenon where the performance or capacity of an entire system is limited by a single or limited number of components or resources. The term bottleneck is taken from the 'assets are water' metaphor. As water is poured out of a bottle, the rate of outflow is limited by the width...
is due to the PCI-Express connection, which is limited to supplying 75 Watts.
Modern video cards with a power consumption over 75 Watts usually include a combination of six-pin (75W) or eight-pin (150W) sockets that connect directly to the power supply
See also
- ATIAtiAs a word, Ati may refer to:* Ati, a town in Chad* Ati, a Negrito ethnic group in the Philippines* Ati-Atihan Festival, an annual celebration held in the Philippines* Ati, a queen of the fabled Land of Punt in Africa...
, NVIDIANVIDIANvidia is an American global technology company based in Santa Clara, California. Nvidia is best known for its graphics processors . Nvidia and chief rival AMD Graphics Techonologies have dominated the high performance GPU market, pushing other manufacturers to smaller, niche roles...
- duopoly of 3D chip GPU and graphics card designers - ATI CrossfireATI CrossFireAMD CrossFireX is a brand name for the multi-GPU solution by Advanced Micro Devices, originally developed by ATI Technologies. The technology allows up to four GPUs to be used in a single computer to improve graphics performance.-First-generation:CrossFire was first made available to the public...
- ATI's proprietary mechanism for scaling graphics performance - Computer display standards - detailed list of standards like SVGA, WXGA, WUXGA, etc.
- Feature connectorFeature connectorThe Feature connector was an internal connector found mostly in some older VESA Local Bus, ISA and PCI graphics cards, but also on some early AGP ones....
- GeForceGeForceGeForce is a brand of graphics processing units designed by Nvidia. , there have been eleven iterations of the design. The first GeForce products were discrete GPUs designed for use on add-on graphics boards, intended for the high-margin PC gaming market...
, RadeonRadeonRadeon is a brand of graphics processing units and random access memory produced by Advanced Micro Devices , first launched in 2000 by ATI Technologies, which was acquired by AMD in 2006. Radeon is the successor to the Rage line. There are four different groups, which can be differentiated by...
– Examples of GPUs. - GPGPUGPGPUGeneral-purpose computing on graphics processing units is the technique of using a GPU, which typically handles computation only for computer graphics, to perform computation in applications traditionally handled by the CPU...
(i.e.: CUDACUDACUDA or Compute Unified Device Architecture is a parallel computing architecture developed by Nvidia. CUDA is the computing engine in Nvidia graphics processing units that is accessible to software developers through variants of industry standard programming languages...
, AMD FireStreamAMD FireStreamThe AMD FireStream is a stream processor produced by Advanced Micro Devices to utilize the stream processing/GPGPU concept for heavy floating-point computations to target various industries, such as the High Performance Computing , scientific, and financial sectors...
) - Graphics hardware and FOSS
- FramebufferFramebufferA framebuffer is a video output device that drives a video display from a memory buffer containing a complete frame of data.The information in the memory buffer typically consists of color values for every pixel on the screen...
- The computer memory used to store a screen image - Mini-DIN connectorMini-DIN connectorThe mini-DIN connectors are a family of multi-pin electrical connectors used in a variety of applications. Mini-DIN is similar to the larger, older DIN connector...
- List of video card manufacturers
- Scalable Link InterfaceScalable Link InterfaceScalable Link Interface is a brand name for a multi-GPU solution developed by NVIDIA for linking two or more video cards together to produce a single output...
- NVIDIA's proprietary mechanism for scaling graphics performance - Texture mappingTexture mappingTexture mapping is a method for adding detail, surface texture , or color to a computer-generated graphic or 3D model. Its application to 3D graphics was pioneered by Dr Edwin Catmull in his Ph.D. thesis of 1974.-Texture mapping:...
- A means of adding image details to a 3D scene - Video In Video Out (VIVO)Video In Video OutVideo In Video Out, usually seen as the acronym VIVO , is a graphics port which enables some video cards to have bidirectional analog video transfer through a mini-DIN connector, usually of the 9-pin variety, and a specialised splitter cable .VIVO is found on high-end ATI and NVIDIA...
- Z-bufferingZ-bufferingIn computer graphics, z-buffering is the management of image depth coordinates in three-dimensional graphics, usually done in hardware, sometimes in software. It is one solution to the visibility problem, which is the problem of deciding which elements of a rendered scene are visible, and which...
– A means of determining visibility.
External links
- Graphics Card Comparisons, Performance, and Specifications
- http://www.gpureview.com