Video card: Glossary

2D Graphics – visual presentation of scenes and objects, described by the coordinates along two axes X and Y, for instance by the height and the width.

3D Graphics – visual presentation of scenes and objects, described by 3D coordinates along three axes X, Y and Z, for instance by the height, the width and the depth.

3D Pipeline – a step-by-step procedure of #D graphics processing, conditionally divided into 3 stages – tesselation, i.e, creation of a structured model of an object, the geometric stage and the rendering process. At the tesselation stage a description of the object’s model is created, which is then converted into a certain polygon set. The geometric stage is concerned about numerous settings, transformation conditions, lighting and others. At the rendering stage, the most important and crucial one for the final result’s quality, the 3D image, formed of polygons on the geometric stage, is transformed into a 2D image for displaying.

3-Way SLI – an advanced version of the SLI technology by NVIDIA, enabling uniting of three video cards within a single system.

AGP (Accelerated Graphics Port) – a specific 32-bit bus designed for video cards’ connection. The existing video cards are typically designed to fit the PCI-Express slot; however AGP-cards are still widely spread since a huge number of platforms for this interface have been released. At the times, AGP bus substituted PCI bus as the processor data rate with the AGP bus (66 MHz) is twice higher then the one of the PCI (33 MHz). Practically, the AGP 1x version was in no time substituted by the 2x due to the insufficient bandwidth. Later AGP 4x and AGP 8x versions having 2 Gb/sec bandwidth were introduced. With the AGP 4x bus being enhanced, the power voltage level was modified – instead of 3.3V the 1.5V AGP 4x cards appeared, and, consequently, the AGP 8x as well.

Accelerator – generally, a card or a board extending the computer options, not necessarily a graphic one – there are also encrypting accelerators, for instance, sound, decoding ones. Typically, an accelerator is a hardware extension processing some data, thus, enabling a faster data processing and lower CPU load. The most common are the 2D/3D video accelerators; therefore, the term ‘accelerator’ is in most cases used in regard to a video card unless other was mentioned before.

Algorithmic Procedure Texturing – a way of image rendering with visually infinite texturing. The term ‘procedure’ denotes a sequence of steps. Texturing is in general a creation of image having numerous properties.

Alpha-Blending – a technology of transparent or semi-transparent objects or image layers creation, which practically means assigning a specific attribute to the entire image or a single pixel, specifying its final view: solid (transmitting no light), invisible (transparent) or semi-transparent. The texture applied onto the object can contain the transparency information (Alpha) beside the color information (Red, Green, Blue). Depending on the value of the Alpha rate different parts of the object acquire various transparency extents which practically means a various color blending extents of the foreground and the background. Adding the Alpha-blending info into the properties of the polygons prepared for rendering enables creation of such particular effects as glass, water and other virtually translucent elements.

Alpha Buffer, Alpha Channel, Alpha Plane – an additional color channel for object’s transparency information. Pixels have 4 numeric characteristics (RGBA); the 32-bit frame buffer describing the 24-bit color – eight bits per a color channel, plus an 8-bit Alpha-channel.

Ambient Light – general level of artificial lighting providing a clear view of all surfaces, even with no direct luminancy, as an option of presentation of infinitely boundlessly dissipated reflections within a visible scene.

Animation – technology of creation of movement-illusion using a sequence (rendering) of static images.

Anisotropic Filtering – process of filtering (or blending) of textures when the averaging of objects’ parameters is realized considering the data of every single polygon and considering all 3 dimensions of the object. The other filtering methods, as a rule, average the color of the reproduced pixel, taking into account the color of original pixels thus making the resulting image too blurred or sharpened.

Anti-aliasing – technology of smoothing by interpolation at the sub-pixel level enabling removing the typical ‘jagged edges’ and presenting of the image in higher resolution. With a 3D scene drawn by machine smoothing can be replaced or enhanced by bilinear and trilinear filtering as these technologies realize a simulation of smoothing.

API (Application Programming Interface) – standardized application programming interface enabling the developers to write applications having no specific knowledge of the hardware platform. API is an attribute of any operational system and is applied as a conventional crypt so that the standard procedures shouldn’t be repeated. As for 3D it means that a game designed for some certain video card having a specific hardware execution won’t run on any other accelerators, meantime the use of API enables the game and equipment manufacturers to ensure that games and accelerators communicate ‘the same language’. The most popular existing 3D API are OpenGL and Direct3D.

Aspect Ratio – a screen format, its width divided by its height. For instance, the resolutions 1920 х 1200, 1680 х 1050, 1280 х 800, 1152 х 720, 1024 х 640 have an aspect ratio of 16:10; resolution 1280 х 1024 has an aspect ratio of 5:4; resolutions 1024 х 768, 800 х 600, 640 х 480 have an aspect ratio of 4:3; resolution 720 х 480 has an aspect ratio of 3:2.

Artifact – is a result of a non-quality or a low-quality texture compression with ‘blurred’ image fragments involved. On 2D and 3D images artifacts can emerge where colors meet.

Atmospheric Effect – effects, like fog effect, making a scene more realistic.

Bilinear Filtering – a method of texturing by anti-aliasing, graphic becoming less pixelated and less blocked. Is used to get smoother textures. In the process of bilinear filtering a processing of four neighbouring pixels takes place, resulting in a pixel having an averaged approximated color. The use of bilinear filtering may cause the object to lose ‘virtual’ depth and natural appearance even especially in the process of slow rotation or replacement of polygons. In this case other types of filtering can help: the trilinear or the anisotropic one.

Bitmap – a bit image, bit (rester) map, quite any image visible on the screen , consisting of an array of dots ordered in vertical or horizontal rows. Every dot (pixel) has its color attribute, the scope of dots forms the image. The more bits are available for the color attribute the larger the color intensity is, the more natural the image is going to look.

Buffer – the memory a special option or a set of options are assigned to.

Bump-Mapping – a visual technique used to convey typical specific bumps to an object’s surface. To do this developers bind as many as two textures to each polygon, one of them being normal, basic, the other – a blended texture, describing the object’s bumps. In case of bump-mapping the light reflected from bumps alters depending on the angle of view like in reality.

Chroma Keying – color managing; the object’s color being removed and another object’s color emerges, the object placed behind and the remote color becoming transparent.

Clock Cycle – the microprocessor’s step. Modern processors, including graphic, perform several hundred or thousand million cycles per second.

Clock Frequency – a parameter showing the speed of integer-value operations performed. The graphic processes’ clock cycle is expressed in MHz (mil. cycles per sec.).

Collision Detection – option of 3D objects to interact with other 3D objects naturally. When you see a box on the floor in a 3D game the box ‘knows’ it is not supposed to fall through the floor. This ‘knowledge’ results from the collision detection. The process of collision detection is being advanced continuously.

Compression – an option of size reduction with no significant graphic details lost. 3D accelerator works faster with compressed textures.

CrossFire X – an advanced version of the CrossFire technology by ATI enabling to unite up to four video processors in one system.

DDR-SDRAM ( Double Data Rate SDRAM) – SDRAM memory offering a double date transfer speed, can transmit a signal to both fronts of the cycle pulse.

Dedicated Frame Buffer – some volume of memory used to store data of the frame and/or Z-buffer.

Direct3D (D3D) – the graphic part of Microsoft DirectX API.

DirectX – an independent programming interface providing communication between the Windows applications and hardware, including the video card. Due to DirectX developers don’t have to write programs for every single video card. This simplifies designing of games and multimedia applications as well as encourages their wide spread. Support of a DirectX version denotes the capacity of a card on the hardware level to perform a certain set of options. The later DirectX version the card supports, the more options there are and, respectively, the wider its capacities in special effect creation are. In case a game was designed on the basis of a new DirectX version and the video card doesn’t support it you won’t enjoy to the fullest all the video effects meant by developers. Modern video cards support the DirectX 11 version. One should mind that DirectX 11 operates only within OS Windows 7.

Displacement Mapping – texturing by displacement, the second texture map used to display the surface bumps. The map shows how on the original texture the bumps’ shadows are dropped.

DisplayPort – DisplayPort interface serves to transmit video and audio in the digital form. This interface is enhanced with unauthorized copying protection DPCP (DisplayPort Content Protection). DisplayPort is positioned as a substitution of the DVI and a competitor of HDMI.

Dithering – smoothing of passages between colors, a visual artefact accompanying the reduction of quantity of the used colors (reduction of color intensity). For instance, as a result of smoothing a texture loses its sharpness, pixelation is going to be clearly seen on it.

Driver – a mediator program between different hardware, OS and other programs. The devices can’t be utilized without drivers.

Engine – a compound of options to perform a certain task. Speaking about games, the engine is the operational basis of a game, designed by developers. Depending on the programming quality and applied options the engine can perform various effects and graphics.

Fill Rate – fill speed, a speed the pixels are drawn on the monitor screen.

Filtering – a process enabling the video card to smooth textures, levelling the pixel color to the neighbouring pixels’ one. Can be bilinear, trilinear and anisotropic.

Fog, Fogging – simulation of fog. Game developers can fog to intensify other effects, like water boiling.

FPS (Frames per Second) – number of frames drawn per second. The higher the video card’s performance is the faster it draws every frame and passes to the next one. As a rule, the higher the monitor resolution is, the fewer frames can be processed by the video card per second.

FSAA (Full Scene Anti-Aliasing) – the gist of the FSAA technology is that the video processor calculates a 3D scene for a greater resolution than the one applied for displaying. Then the image is compressed to the required size resulting in substantial reduction of the ‘jagged’ effect. The maximum FSAA extent shows in how many times the calculation resolution can exceed the required one. One should consider that the high FSAA extent may reduce significantly the drawing speed, thus reducing the video card performance in computer games. Typically a video card has several FSAA levels enabling to choose an optimal value depending on specific conditions.

Gamma Correction – an ability to manage the paint, the green or the blue pixel or texture component to detect the needed brightness.

Gouraud Shading – shading algorithm named after the creator – Henry Gouraud. The Gouraud method, or the color interpolation, enables achieving of smooth shading on an object’s surface. At all object’s heights vector normals are built and depending on the angle between normals and the direction to the light source the pixel color corresponding with the polygons’ vertexes is defined. The pixels’ colors are interpolated (between the vertexes) across the polygons’ surface.

Graphics Controller, Graphics Processor, Graphics Processing Unit (GPU) – 2D or 3D processor combining all the graphic conveyor’s options. Originally designed to unload the CPU the present GPU transformed into a powerful PC component comprising beside 2D/3D video processing a number of related options, for instance, DVD and/or HD video decoding, videosignal input/output.

HDCP (High-bandwidth Digital Content Protection) – a protection technology based on check of special digital keys at the digital signal source (a digital player, a PC, a game console) and at the receiver (HDTV-set or a plasma display). If the keys are in order the transmission of high-resolution audio and video data is allowed. If the TV-set’s digital interface doesn’t support the HDCP technology a low quality video will be displayed on the screen. With the help of a video card supporting HDCP and an optical Blue-Ray or HD-DVD drive you can play high-resolution films on your PC or watch them on HDTV-sets. HDCP support is applied in DVI and HDMI interfaces.

HDMI (High Definition Multimedia Interface) – an interface used for digitalized videosignal or multichannel audio transmission. The interface is enhanced with the High-bandwidth Digital Content Protection (HDCP). HDMI was designed specially for the new high-definition digital television standard – HDTV. With the help of HDMI you can plug digital TV-sets and plasma displays supporting the new digital TV standard to your video card. The HDMI is backward compatible with DVI. That means that by means of a special adaptor for HDMI connector a display with DVI can be plugged in.

Internal Rendering – color intensity at the internal image processing by the video card.

Interpolation – mathematic method of restoration of lost or absent information. For instance, when a 150х150 pixel bit is scaled to 300х300 the necessary pixels are interpolated as the medium value of the neighbouring pixels.

Jaggies – a slang name for a jagged bit effect, visible on bit graphics when the curves or bit texts are zoomed. Partially or completely smoothed by anti-aliasing.

Layer – the image level which can be changed and edited regardless of the changes in other resulting image’s parameters.

Lighting Effects – luminancy effects simulating light in 3D graphics. It is realized due to lighting of textures and pixels near to the virtual source of light. Lighting is one of the nicest video card options increasing greatly the graphics perception.

Mip-Mapping – the process is based on transformation of an image or a texture into smaller images. The algorithm uses textures with different resolutions (256x256,128x128,64x64, etc.) for different parts of the object depending on the distance between the observer and the surface and on the angle the surface is inclined. The negative side effect of mip-mapping is the so-called banding (breaks between mip-levels), and in some cases – reduction of texture sharpness.

Multitexturing – process of multiple textures applying to the object at a 3D game design. Multitextures may be laid on each other to display roughness of surfaces or used together to create a single large 3D model; texel colors blending according to a certain law.

OpenGL (Open Graphic Library) – a computer graphic development standard often used to write a professional graphic software. Presently the latest version of OpenGL is 3.2. One should note that modern games are more oriented on utilization of DirectX, so, this parameter may be important only for a specialised software.

OpenGL ICD - aninstallable client driver.

Overclocking – "acceleration" of the regular clock frequency of the graphic processor of a video card and/or of the clock frequency of graphic video-memory excelling the values indicated in the passport. Today the video cards manufacturers incorporate the overlocking right into drivers; traditionally overlocking used to be carried out by modifying the BIOS parameters of a video card, before that – by bridges on cards.

PCI (Peripheral Component Interface) – an industrial computer extension standard for plugging of various devices – network cards, controllers, etc.

PCI Express (PCI-E) – the new generation of computer buses with serial architecture providing in the first generation performance of more than 4 Gb/sec in both directions. The serial architecture of the PCI Express bus enables combining of the so-called PCI Express lanes to increase the maximum performance of the resulting bus. Unlike the AGP bus, the PCI Express standard doesn’t involve an exclusive use of PCI-E to handle 3D graphic, however, the PCI Express x16 slot are mostly used along with graphic accelerators.

Per-Pixel Mip-Mapping – the most accurate version of MIP-mapping. To increase the performance mip-mapping can apply not only to a pixel but also to a polygon, but only mip-mapping provides shadows as much detailed as the objects dropping them.

Perspective Correction – the process is based on the option to display correctly the texture from any perspective.

Phong shading – one of the finest shading types differing from Gouraud Shading algorithm by the normals’ vectors built for each dot of the image and, respectively, requiring greater number of calculations.

Pixel – a minimal object on the display screen.

Pixelation – a visually seen texture bit in a game at close approximation or in a game having high resolution with settings like 640x480.

Polygon – a closed 2D figure. Polygons are combined with hundreds of other figures to create an integrated model in 3D engines.

Projection – a process of 3D view transformation into a 2D image for displaying.

Quad SLI – an advanced version of the SLI technology by NVIDIA enabling combination of four video processors in one single system.

Raytrace – this method involves calculation of the virtual ray of light from the source across all reflecting surfaces up to the object the light drops on. The method creates utterly realistic effects as well as transparent surfaces.

Realtime – an action performed by a computer at the same speed it goes in reality.

Reflective Mapping – displaying of reflecting surfaces enabling creation of textures with true-to-life realistic reflection of the surrounding objects.

Refresh Rate – the frequency offered by a display to reproduce series of static images. Is measured in Hertz (Hz), for instance, 100 Hz refresh rate means that a frame is replaced 100 times per second.

Resolution – a number of pixels along the horizontal axis multiplied on the number of pixels along the vertical axis, for instance 1920 х 1200 – a product giving the overall number of displayed.

Shaders – the microprograms enabling such effects as metallic glow, water surface, realistic voluminous fog, various object deformations, motion blur effect and others. The higher the Shaders’ version is the more options a video card has to create special effects. Currently the new video cards support the Shaders’ versions 4.0 or 5.0.

SIMD (Single Instruction Multiple Data) – an instruction enabling the processor to perform an identical operation over several data flows, thus, discharging the processor from a repeated introduction of the same instruction.

SLI/CrossFire – the technologies SLI by NVIDIA and CrossFire by ATI enable to combine the computational power of two video cards mounted on one motherboard. Simultaneous use of two video cards may be of interest in cases when it is necessary to get a super-powerful video system excelling all existing individual video cards in speed. To realize the SLI/CrossFire technologies it’s necessary for a motherboard to have two PCI-E slots for video cards. Besides, the motherboard must as well support SLI/CrossFire. It is worth mentioning that SLI requires that both video cards installed be identical, while CrossFire needs only that one of the two video cards be ATI CrossFire Edition.

Software Rendering – an obsolete method of software rendering involving no 3D video cards, slow and unbeautiful.

Specular highlight – flares (reflecting lighting), imitation of direct reflection of the source of light.

Sprite – 2D graphic image.

Stencil buffer – a section of graphic memory having the size of a frame displayed and storing stencil data which may be used to hide or display some pixel in various cases, for example, for line ‘hatching’, simulation of simple shadows, reflections, smooth transition, etc.

T&L, Transform and Lighting – two separate hardware display controller module-engines responsible for rendering process. Transform module detects the complicity level of displayed objects; Lighting module is responsible for conveying of a realistic effect to a scene by changing the light sources’ parameters.

Texel (TEXture ELement) – a common name of pixel in 3D.

Texture – graphic image (bit), ‘wrapped’ over the polygonal 3D frames. Textures help to create that amazing 3D world we see in games.

Texture Compression – a video card option to reduce image size by compressing repeated lines and decreasing of the color set intensity. Texture compression may dramatically increase the frame change frequency, however the quality may go down.

Texture Mapping – process of texture (bit) ‘wrapping’ over polygonal 3D frames.

Transparency – property of objects one can clearly or partially see other objects through.

Triangles per second – the speed of triangle processing by a graphic controller, standard conventional industrial indicator describing the performance. The more triangles are processed per second the higher the performance is.

Trilinear Filtering – process of bilinear filtering application to each side of a texture. Improves the imaxe definition and removes pixelating. Not only pixels get filtered, but also MIP-levels, i.e., first the colors of two pixels in two (neighbouring) MIP-levels are calculated, then these two values are mixed. The only shortcoming of trilinear filtering is texture sharpness loss.

TurboCache/HyperMemory – the technologies TurboCache by NVIDIA and HyperMemory by ATI enable videoprocessor to use a part of computer RAM to process video images. The support of these modes is possible only in video cards having the PCI-E bus. TurboCache/HyperMemory is used in inexpensive low-end models. Due to these technologies manufacturers can mount just 32 Mb or 64 Mb of video memory on video cards but the video processor can use as many as 256 Mb.

Tweak – optimization of an application or hardware parameters to increase performance, raise stability, etc.

TV-out – the connector a common TV-set can be plugged in at a video card. As a rule, the S-Video connector is installed on a video card; a TC-set can be connected to the composite signal (RCA connector) by means of a specific cable.

Vertex – a point in 3D space having specified coordinates, usually described by X, Y and Z coordinates. Vertex is one of fundamental structures in polygonal modelling: two vertexes may be used to define lines, three – to define a triangle, etc.

VIVO (Video Input Video Output) – this video output serves to plug an analogic video camera or a video player to a computer. Having all necessary software installed the received video signal can be digitized and recorded on a DVD, for instance. By means of TV output a video card can be connected to a normal TV-set. Typically, a special cable ending with connectors as follows: S-Video input/output and composite RCA in/out, is connected to VIVO.

Volumetric Lighting – effect of light passing through a 3D obstacle, such as fog, dust cloud, smoke, vapor and so on.

Volumetric Fogging – spacial or ‘virtual’ fog hiding non-drawn remote textures to increase performance.

Z-Buffer – a part of a 3D accelerator memory serving to store the coordinates of Z-points in 3D space with the axes X, Y and Z. The use of the Z-buffer enables a video card not to draw the textures supposed to be hidden by other textures. For example, if you turn around a wall in a game you can’t see other objects through it, and the Z-buffer helps the card not to draw them uselessly. The Z-buffer enables considerable performance growth. Moreover, it helps to improve the Z-positioning accuracy.

Quantity of Displays Supported – some video cards can operate several displays. This enables a user to expand the displayed area. One can for instance, extend the ‘Desktop’ on two displays or set the settings the way one display showed one window and the other – the second one. It’s possible to display a text editor on one screen and a multimedia player with a film – on the other. In the professional sphere use of several displays is applied to different fields: the automatic designing, geoinformational systems, 3D-modelling. The majority of modern video cards support two displays; some specialized professional video adapters enable connection of eight displays.

Video Card Model Range – manufacturers produce series of models united under one general concept, under one name. Presently NVIDIA is releasing graphic processors for wide use named GeForce, while ATI – the Radeon range. Quadro and FireGL are model ranges for workstations by NVIDIA and ATI respectfully. 3Dlabs manufactures video processors for professional use named Wildcat; Matrox produces Parhelia and Millennium.

Video Processor’s Name – a graphic processor provides almost all basic properties of a video card its performance depends on. The classes of most popular graphic processors are given below:
· High-end class: ATI (models Radeon HD 5970, HD 5870, HD 5850),NVIDIA (models GeForce GTX 295, GTX 285, GTX 275)
· Medium class: ATI (models Radeon HD 5770, HD 5750, HD 4890, HD 4870, HD 4850), NVIDIA (models GeForce GTX 260, GTS 250, 9800 GT, 9600 GT)
· Low-end models: ATI (models Radeon HD 4650, HD 4550), NVIDIA (models GeForce GT 240, GT 220)

Additional Power Supply for a Video Card – the necessity in additional video card power supply directly from the PC power supply. While operating the modern video adapters consume considerable amount of electric energy. Power supply provided through the motherboard slot is not sufficient for them. Therefore, their design includes the option of connection to the PC power supply directly through additional connectors. Before buying a high-performance video card requiring extra power one must ensure that his PC power supply has sufficient power potential (at least 500-600 Wt).

Video Memory Volume– in modern video card models memory is set in the volume from 256 Mb (for low-end models - 256 Mb, for medium class - 256-512 Mb, for high-end - 512 Mb and more). The video memory stores an image (screen frame), as well as elements necessary to build a 3D image. A large memory volume is required for new computer games.

Passive Cooling – a system of cooling based on the absence of a cooler. Cooling is carried out due to redirecting of heating energy. The heat is removed from warming components by radiators and/or heating pipes. Absence of a cooler is an advantage as you get rid of its noise. Unfortunately, modern high-performance video cards can’t operate without coolers. Passive cooling system is installed only on models having the first and medium levels.

Water Cooling Support – water cooling is more efficient than the air one thus enabling manufacturers to increase significantly the video card performance. Typically, the water cooling system itself isn’t included into the kit, one should buy it separately.

Video Processor Performance– name of the manufacturing company the video card was built by. Today there are two leading manufacturers on the video processor market: ATI and NVIDIA. Matrox and 3Dlabs companies are specialized in graphic processors for professional use.

Video memory Type– in modern video processors the following video memory types are used: GDDR, GDDR2, GDDR3, GDDR4, GDDR5. GDDR – is the memory based on the Double Data-Rate technology. It is utilized in low-end models of modern video cards. GDDR2 can operate at higher frequency than the previous generation. It is not widely spread due to its considerable heat emission. GDDR3 is based on the same technology the GDDR2 is. Some enhancements help it to work at higher frequency but with lower heat emission. It is used in many modern video card models. The memory of the GDDR4 standard has higher performance compared to GDDR3. It can work at access time up to 0.6 ns, i.e. at a frequency of 3330 MHz. Another benefit of GDDR4 before the previous generation of videomemory is lower power consumption. GDDR5 is characterized by higher data exchange rate compared to the predecessors. That enables to raise noticeably the video card performance, especially in complicated modes with smoothing.

Type of Card Connection is the type of slot the video card is installed in. Data exchange between a video card and the motherboard goes throughout the slot. To choose a video card it is necessary to consider what kind of slot is used in your motherboard. The two most common types of video card connection are AGP and PCI-E. AGP (Accelerated Graphics Port) is a bus format developed on the basis of outdated PCI slot especially for high-performance video adapter connection. Few years ago AGP was almost the only way of video card connection, nowadays the number of video adapters having this interface is smaller. Modern models of video cards use standard AGP 8X, which provides a speed up to 2.1 Gb/sec. If only the AGP slot is installed on your motherboard you should choose among video cards having the AGP interface. PCI-E (PCI Express) is a new bus standard for personal computers, that is presently replacing PCI and AGP. The PCI Express channel bandwidth can be scaled by adding data channels, in this case respective modifications (PCI-E x1, x4, x8, x16) are obtained. Modern video card models of use PCI-E 16x standard providing a speed up to 8 Gb/sec.
Some motherboard models enable to set 2 PCI-E video cards at the same time, in this case the power of graphic system increases almost in twice. This technology is called SLI (enhanced by NVIDIA) and CrossFire (produced by ATI).

Video Processor Cycle - is the clock cycle of the graphic processor core. The video processor cycle depends largely on the performance of a video system. However, with the processor cycle increased, its heat emission increases as well. That's why it is necessary for modern high-performance video systems to install a powerful cooling system that occupies additional space and often makes noise while operating. One should mind that the graphic processor cycle is not the only parameter the performance of the system depends on. New models of graphic processors do not always work at a higher cycles than the previous ones because a microsystem having a sophisticated structure may fail at this cycles.

Exchange Memory Bus – is the capacity of the memory bus, in other words, the number of data bits which can be transferred per cycle. The memory performance can be denoted as the amount of data transferred per a unit of time. It depends directly on the memory cycle and on the bus capacity. A bus of 256 bit and more is used for data exchange with the videomemory in high-end video cards. In low-end and medium models a 256 bit bus or a 128 bit bus is used.