Video card
Most video cards are not limited to simple display output. Their integrated graphics processor can perform additional processing, removing this task from the central processor of the computer[1]. For example, Nvidia and AMD (ATi) produced cards render the graphics pipeline OpenGL and DirectX on the hardware level[2]. In the later 2010s, there has also been a tendency to use the computing capabilities of the graphics processor to solve non-graphic tasks[3].
Usually the graphics card is made in the form of a printed circuit board (expansion board) and inserted into an expansion slot, universal or specialized (AGP, PCI Express)[4]. Some have been made using dedicated enclosures, which are connected to the computer via adocking station or a cable.
A video card (also called a display card,graphics card, display adapter or graphics adapter) is an expansion card which generates a feed of output images to a display (such as a computer monitor). Frequently, these are advertised as discrete or dedicated graphics cards, emphasizing the distinction between these and integrated graphics. At the core of both is the graphics processing unit (GPU), which is the main part that does the actual computations, but should not be confused as the video card as a whole, although "GPU" is often used to refer to video cards.
History
Standards such as MDA, CGA, HGC, Tandy,PGC, EGA, VGA, MCGA, 8514 or XGA were introduced from 1982 to 1990 and supported by a variety of hardware manufacturers.
3dfx Interactive was one of the first companies to develop a GPU with 3D acceleration (with the Voodoo series) and the first to develop a graphical chipset dedicated to 3D, but without 2D support (which therefore required the presence of a card 2D to work). Now the majority of modern video cards are built with either AMD-sourced or Nvidia-sourced graphics chips.[5] Until 2000, 3dfx Interactive was also an important, and often groundbreaking, manufacturer. 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). Video cards also have sound card capabilities to output sound – along with the video for connected TVs or monitors with integrated speakers.
Graphics cards weren't very useful for early computers, since they didn't have the capability to run graphic-based games or high-resolution videos as modern computers do now. Early computers had very little processing power with the on-board integration compared to today's systems. The graphics cards on these earlier systems ran at significantly lower power consumption, but at very low 2D performance. You would often be able to see the refresh rate of the monitor compared to todays high refresh rate monitors powered by Nvidia and AMD's new architectures.
Within the industry, video cards are sometimes called graphics add-in-boards, abbreviated as AIBs,[5] with the word "graphics" usually omitted.
Dedicated vs integrated graphics
Classical desktop computer architecture with a distinct graphics card over PCI Express. Typical bandwidths for given memory technologies, missing are the memory latency. Zero-copy between GPU and CPU is not possible, since both have their distinct physical memories. Data must be copied from one to the other to be shared.
As an alternative to the use of a video card, video hardware can be integrated into themotherboard, CPU, or a system-on-chip. Both approaches can be called integrated graphics. Motherboard-based implementations are sometimes called "on-board video".. Almost all desktop computer motherboards with integrated graphics allow the disabling of the integrated graphics chip in BIOS, and have aPCI, or PCI Express (PCI-E) slot for adding a higher-performance graphics card in place of the integrated graphics. The ability to disable the integrated graphics sometimes also allows the continued use of a motherboard on which the on-board video has failed. Sometimes both the integrated graphics and a dedicated graphics card can be used simultaneously to feed separate displays. The main advantages of integrated graphics include cost, compactness, simplicity and low energy consumption. The performance disadvantage of integrated graphics arises because the graphics processor shares system resources with the CPU. A dedicated graphics card has its own random access memory (RAM), its own cooling system, and dedicated power regulators, with all components designed specifically for processing video images. Upgrading to a dedicated graphics card offloads work from the CPU and system RAM, so not only will graphics processing be faster, but the computer's overall performance may also improve.
Both AMD and Intel have introduced CPUs and motherboard chipsets which support the integration of a GPU into the same die as the CPU. AMD markets CPUs with integrated graphics under the trademark Accelerated Processing Unit (APU), while Intel markets similar technology under the "Intel HD Graphics and Iris brands. Although they are still not equivalent to the performance of discrete solutions, Intel's HD Graphics platform provides performance approaching discrete mid-range graphics, and AMD APU technology has been adopted by both thePlayStation 4 and Xbox One video game consoles.[6][7][8]
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. For example, the thermal design power (TDP) for the GeForce GTX TITAN is 250 Watts.[9] While CPU and power supply 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.[10][11] Although power supplies are increasing their power too, thebottleneck is due to the PCI-Expressconnection, which is limited to supplying 75 Watts.[12] Modern video cards with a power consumption over 75 Watts usually include a combination of six-pin (75 W) or eight-pin (150 W) sockets that connect directly to the power supply. Providing adequate cooling becomes a challenge in such computers. Computers with multiple video cards may need power supplies in the 1000–1500 W range. Heat extraction becomes a major design consideration for computers with two or more high end video cards.
Size
Video cards for desktop computers come in one of two size profiles, which can allow a graphics card to be added even to small-sized PCs. Some video cards are not of usual size, and are thus categorized as being low profile.[13][14] Video card profiles are based on width only, with low-profile cards taking up less than the width of a PCIe slot. Length and thickness can vary greatly, with high-end cards usually occupying two or three expansion slots, and with dual-GPU cards -such as the Nvidia GeForce GTX 690- generally exceeding 250 mm (10 in) in length.[15] Generally, most users will prefer a lower profile card if the intention is to fit multiple cards or they run into clearance issues with other motherboard components like the DIMM or PICE slots. This can be fixed with a larger case that comes in sizes like mid tower and full tower. Full towers can usually fit larger motherboards in sizes like ATX and micro ATX. The larger the case, the larger the motherboard, the larger the graphics card or multiple other components that will acquire case real-estate.
Multi-card scaling
Some graphics cards can be linked together to allow scaling of the graphics processing across multiple cards. This is done using either the PCIe bus on the motherboard, or, more commonly, a data bridge. Generally, the cards must be of the same model to be linked, and most low power cards are not able to be linked in this way.[16] AMD and Nvidia both have proprietary methods of scaling,CrossFireX for AMD, and SLI for Nvidia. Cards from different chipset manufacturers, architectures cannot be used together for multi card scaling. If a graphics card has different sizes of memory, the lowest value will be used, with the higher values being disregarded. Currently, scaling on consumer grade cards can be done using up to four cards.[17][18][19] The use of four cards requires a large motherboard with a proper configuration. Nvidia's GeForce GTX 590 video card has the ability to be configured in this four card configuration[20]. As stated above, users will want to stick to the same performance card for optimal use. Motherboards like ASUS Maximus 3 Extreme and Gigabyte GA EX58 Extreme are certified to work with this configuration[21]. For proper performance of your 4 card configuration, it's recommend to use a core i7 CPU with turbo boost to avoid the bottleneck throughput. A certificated large power supply is necessarily to run the cards in SLI or CrossFireX. Power demands must be known before a proper supply is installed. For the four card configuration, a 1000+ watt supply is needed. AcBel PC8055-000G and Corsair AX1200 supplies are examples[22]. With any powerful video card like a GTX 1060+ or 1080, thermal management can be overlooked. Video cards require a well vented chassis and thermal solution. Water or air cooling are required for all video cards, with larger configurations needing water solutions to achieve proper performance[23].
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