What is a video card? Graphics adapter? The device of a modern video card.
Very often, many computer and laptop users are faced with a rather unpleasant situation when, after reinstalling the operating system, discrete graphics accelerators installed directly on motherboard, disappear from the list of equipment presented in the “Device Manager”. In this case, instead of his own video card, the user sees some kind of video controller (VGA-compatible), which is marked with a yellow triangle with exclamation mark, which indicates that the driver for it is not installed. It also happens that the device does not seem to be marked as a device without a driver, but when launching the same games, serious problems begin, since they do not detect the required graphics adapter in the system. Why this happens and what actions can be taken in such a situation will be discussed further.
What is a video controller (VGA-compatible) in Device Manager?
Let's start with the fact that such a device, displayed in the list of equipment in Device Manager, is only indirectly related to a non-working graphics adapter. It’s just that the system detects the video card not as equipment on board, but as a certain virtual adapter. You can sometimes guess that this is an “iron” card by the fact that it is often indicated that it is a PCI video controller (VGA-compatible). The PCI slot on the motherboard is precisely used for installing a graphics adapter. But, again, the operating system sees it exclusively in the form virtual controller. Why?
Why is the wrong driver installed?
Problem incorrect installation drivers is most often due to the fact that in its own database Windows data does not find the necessary control software for the graphics adapter (if anyone doesn’t know that during the initial installation and during the repeated installation, it uses exclusively its own driver databases).
Another very common situation is that when you reinstall the system without formatting system partition, the new installed OS may inherit errors from the old one, in which the graphics adapter drivers were not completely removed. Because of this, conflicts arise, and Windows itself installs the most suitable driver (as it seems to it), which is completely unsuitable for the functioning of the video card. True, you can also come across cases when the name of the video card seems to be displayed, but the system still shows that the driver for a card that is not present in the system is installed, namely a VGA-compatible video controller (NVIDIA, for example). For GeForce series devices, the reason lies precisely in the fact that outdated drivers were not completely removed.
How to reinstall the driver for a VGA-compatible video controller using the simplest method?
Despite such conflicts, the situation can be corrected quite simply.
First of all, in the “Device Manager”, select a VGA-compatible video controller in the list, and then through the RMB menu, select the driver update item, then instruct the system to search for updated drivers. If this does not help, it is quite possible that the solution to the problem will be to roll back the driver (only if the corresponding button in the adapter properties section is active).
If this does not work, simply remove the device from the system and see how correctly the graphics adapter is detected after that (in some cases this happens instantly, and sometimes you may need to reboot the system).
Application of automated programs and databases
In the case of discrete graphics chips, you can also use the driver disk that was supplied when you purchased them. Another good way to solve the problem is to visit the manufacturer’s official website, where you can find the latest software based on the video card model.
For NVIDIA and ATI adapters, manufacturers often provide additional programs, which also allow you to install or update (for example, NVIDIA Experience). If their use does not give anything, try using automated programs like DriverPack Solution or Driver Booster. The first utility contains its own database, which is much larger than the one used by Windows. And both update applications can access official resources manufacturers via the Internet to download and install updates. You can also use some informative utilities.
For example, in popular program Everest, when viewing information about image output devices for a video card, you can also download drivers.
What to do if the driver cannot be found?
If none of the above helped, but in the list graphics devices still, only a VGA-compatible video controller is present, use the “Device Manager”, through the RMB menu, call up the section of its properties, go to the details tab, from the drop-down list, set the display of equipment ID, copy or write down the most long string with identifiers DEV and VEN, then use it to search for a driver on the Internet, download the necessary software and install it yourself.
Note: If you receive errors when installing the found driver, you will have to remove all drivers manually. To do this, perform an analysis in the program Driver Sweeper, delete all found elements, go to the registry (regedit), search for keys by the name of the video card manufacturer, delete everything that is found, restart the computer and try to install the drivers again. Sometimes the problem may be related to PhysX components, so it is possible that you will have to remove them too.
Video card
Video card (also known as graphics card, graphics card, video adapter) (English videocard)- a device that converts an image stored in the computer's memory into a video signal for the monitor.
Usually the video card is an expansion card and is inserted into connector extensions, universal (ISA, VLB,PCI,PCI-Express) or specialized ( AGP), but it can also be built-in (integrated).
Modern video cards are not limited to simple image output; they have built-in graphics microprocessor, which can perform additional processing, relieving the central CPU computer. For example, all modern NVIDIA video cards and AMD( ATi) support OpenGL applications in hardware.
Video cards have following standards
On PS/2 computers, most of the video adapter circuitry is located on system board. This video adapter contains everything electronic circuits, necessary to support the VGA specification, on a single full-size board with an 8-bit interface.
BIOS VGA is a program designed to manage VGA circuits. Through BIOS programs can initiate some VGA procedures and functions without accessing the adapter.
All VGA equipment provides display of up to 256 shades on the screen from a palette of 262,144 colors (256 KB). An analog monitor is used for this.
If problems arise when booting the system, it boots into safe mode, where the default is VGA adapter in 640x480 mode, 16 colors.
SuperVGA Super Video Graphics Array. Provides higher resolution than the VGA standard. Supports operating modes with resolutions of 800:600, 1024:768, 1280:1024 pixels (or more) with simultaneous display of 2 in 4, 8, 16, 32 degrees of color.
With adapters SVGA various models from different manufacturers you can communicate through a single software interface VESA
Existing standard VESA on boards SVGA provides the use of almost all common image formats and color coding options, up to a resolution of 1280x1024 pixels with 16,777,216 shades (24-bit color coding).
A modern video card consists of the following parts:
Bios (Basic Input/Output System - basic system I/O). The video adapter BIOS contains basic commands, which provide an interface between the video adapter hardware and software. BIOS that can be modified using software, called flash BIOS.
Graphics processing unit (graphics processing unit)- deals with calculations of the output image, relieving the central processor of this responsibility, and makes calculations for processing three-dimensional graphics commands. It is the basis of the graphics card; the performance and capabilities of the entire device depend on it. Modern GPUs in complexity they are not much inferior to the central processor of a computer, and often surpass it both in the number of transistors and in computing power, thanks to a large number universal computing units. However, the architecture GPU The previous generation usually involves the presence of several information processing units, namely: a 2D graphics processing unit, a 3D graphics processing unit, in turn, usually divided into a geometric kernel (plus a vertex cache) and a rasterization unit (plus a texture cache), etc.
Video controller- responsible for forming an image in video memory, gives commands RAMDAC to generate scanning signals for the monitor and processes requests from the central processor. In addition, there is usually an external data bus controller (for example, PCI or AGP), internal data bus controller and video memory controller. The width of the internal bus and video memory bus is usually larger than the external one (64, 128 or 256 bits versus 16 or 32); many video controllers also have built-in RAMDAC. Modern graphics adapters ( ATI, nVidia) usually have at least two video controllers that operate independently of each other and simultaneously control one or more displays each.
Video memory- acts as a frame buffer in which the image is stored, generated and constantly changed by the graphics processor and displayed on the monitor screen (or several monitors). Video memory also stores intermediate image elements invisible on the screen and other data. Video memory comes in several types, differing in access speed and operating frequency. Modern video cards are equipped with memory type DDR, DDR2, GDDR3, GDDR4 and GDDR5. It should also be borne in mind that in addition to the video memory located on the video card, modern graphics processors usually use part of the total system memory computer, direct access to which is provided by the video adapter driver via the bus AGP or PCIE.
Digital-to-analog converter (DAC, RAMDAC - Random Access Memory Digital-to-Analog Converter)- serves to convert the image generated by the video controller into color intensity levels supplied to an analog monitor.
Video ROM- a permanent storage device in which video BIOS, screen fonts, service tables, etc. are written. ROM is not used directly by the video controller - only the central processor accesses it. The video BIOS, stored in ROM, ensures initialization and operation of the video card before loading the main operating system, and also contains system data that can be read and interpreted by the video driver during operation (depending on the method used sharing of responsibilities between the driver and the BIOS). On many modern maps electrically reprogrammable ROMs are installed ( EEPROM, Flash ROM), allowing the video BIOS to be rewritten by the user himself using a special program.
Cooling system- designed for preservation temperature regime video processor and video memory are within acceptable limits.
Video adapter - This electronic board, which processes video data (text and graphics) and controls the operation of the display. Contains video memory, input/output registers and a BIOS module. Sends ray brightness control and image scanning signals to the display .
The most common video adapter today is SVGA adapter(Super Video Graphics Array - super videographic array), which can display on the display screen 1280x1024pixels at 256 colors and 1024x768 pixels at 16 million colors.
With the increasing number of applications using complex graphics and video, a variety of video adapters are being widely used along with traditional video adapters. computer video signal processing devices:
Rice. 2.12. Graphics accelerator
Graphics accelerators (accelerators) - specialized graphics coprocessors, increasing the efficiency of the video system. Their use frees the central processor from a large amount of operations with video data, since the accelerators independently calculate which pixels to display on the screen and what their colors are.
Frame grabbers , which allow you to display a video signal from a VCR, camera, laser player, etc. on a computer screen, so that capture the desired frame into memory and subsequently save it as a file.
TV tuners - video cards that turn a computer into a TV. The TV tuner allows you to select any desired television program and display it on the screen in a scalable window. This way you can monitor the progress of the transfer without stopping your work.
2.13. Keyboard
Computer keyboard - a device for entering information into a computer and supplying control signals. Contains standard set typewriter keys and some additional keys - control and function keys, cursor keys and a small numeric keypad.
All characters typed on the keyboard are immediately displayed on the monitor at the cursor position ( cursor- a glowing symbol on the monitor screen indicating the position at which the next character entered from the keyboard will be displayed).
The most common keyboard today is with a key layout QWERTY(read “querti”), named after the keys located in the upper left row of the alphanumeric part of the keyboard:
Rice. 2.13. Computer keyboard
This keyboard has 12 function keys located along the top edge. Pressing function key results in sending to the computer not just one character, but a whole set of characters. Function keys can be programmed by the user. For example, in many programs, to get help (hints) the key is used F1, and to exit the program - the key F10.
Control keys have the following purpose:
Small numeric keypad used in two modes - entering numbers and controlling the cursor. These modes are switched using the key Num Lock.
The keyboard contains a built-in microcontroller (local control device), which performs the following functions:
sequentially polls the keys, reading the input signal and generating a binary scan code keys;
controls the keyboard indicator lights;
Conducts internal diagnostics of faults;
interacts with central processor through I/O port keyboards.
The keyboard has built-in buffer- small intermediate memory where entered characters are placed. If the buffer overflows, pressing a key will be accompanied by a sound signal - this means that the character was not entered (rejected). The operation of the keyboard is supported by special programs “hardwired” into BIOS, and driver keyboard, which provides the ability to enter Russian letters, control the speed of the keyboard, etc.
The signals supplied to the monitor come from the video adapter built into the system or connected to the computer.
There are three ways to connect computer systems to a CRT or LCD monitor:
Separate video cards. This method, which requires AGP or PCI expansion slots, provides the highest level of efficiency and maximum operational flexibility in choosing the amount of memory and capabilities required (Figure 17);
A graphics chipset built into the motherboard. The lowest cost graphics configuration and fairly low efficiency, especially for 3D games or graphics applications. Resolution and color rendering capabilities are lower than when using separate video adapters, and the amount of memory is almost impossible to change;
Figure 15 – Appearance video adapter
The following components are required for the video adapter to work:
BIOS (Basic Input/Output System - basic input/output system);
The video adapter BIOS, like the system BIOS, is stored in a ROM chip; it contains basic commands that provide the interface between the video adapter hardware and the software. The program that accesses the video adapter's BIOS functions can be a standalone application, operating system or system BIOS. Accessing BIOS functions allows you to display monitor information during POST and begin booting the system before loading any other driver software from disk. The BIOS of a stand-alone video adapter does not depend on the motherboard BIOS. When using a video adapter built into the system logic set, the BIOS of the motherboard and the video adapter are common.
The graphics processor is a video accelerator chip with a limited set of functions. This architecture, used in many video adapters presented on the modern computer market, assumes that the electronic circuits of the video adapter solve algorithmically simple, but time-consuming tasks. In particular, the electronic circuits of the video adapter construct graphic primitives - straight lines, circles, etc., while the computer's central processor is left to construct the image, decompose it into components and send instructions to the video adapter, for example: draw a rectangle of a certain size and color.
Modern graphics systems also use a three-dimensional graphics processor (3D graphics), which is used in almost all video adapters optimized for computer games, as well as in most of the most common video cards. The 3D graphics processor, which is a 3D graphics processing unit, is located in the accelerator chipset and is used to generate polygon images, create lighting effects, and draw halftones.
Video memory. When forming an image, the video adapter accesses memory. The memory capacity on the video adapter (video memory) can vary: from 4 to 512 MB and higher. Additional memory does not increase the speed of the video adapter, but it allows you to increase image resolution and/or the number of reproduced colors. Video adapters built into the system logic use part random access memory strictly limited in BIOS settings.
The amount of memory required to create a mode with a given resolution and number of colors is calculated as follows. Each pixel in an image requires a certain amount of memory to encode, and the total number of pixels is determined by the given resolution. For example, at a resolution of 1,024x768, the screen displays 786,432 pixels.
If this resolution supported only two colors, then only one bit of memory would be needed to display each pixel, with a bit with a value of 0 defining a black point and a bit with a value of 1 defining a white point. By allocating 24 bits of memory to each pixel, more than 16.7 million colors can be displayed, since the number of possible combinations for a 4-bit binary number is 16,777,216 (i.e. 2 24). By multiplying the number of pixels used at a given screen resolution by the number of bits required to display each pixel, we obtain the amount of memory required to generate and store images in this format. Below is an example of such calculations:
1,024 × 768 = 786,432 pixels × 24 bits/pixel = 18,874,368 bits = 2,359,296 bytes = 2.25 MB
The video adapter's digital-to-analog converter (commonly called RAMDAC) converts computer-generated digital images into analog signals that a monitor can display. The speed of a digital-to-analog converter is measured in MHz; The faster the conversion process, the higher the vertical regeneration frequency. In modern high-performance video adapters, performance can reach 300 MHz and higher.
As the speed of the digital-to-analog converter increases, the vertical refresh rate increases, which allows you to achieve more high resolution screen at optimal refresh rates (72–85 Hz or more). As a rule, video adapters with speeds of 300 MHz and higher support resolutions up to 1,920x1,200 at refresh rates of more than 75 Hz. Of course, do not forget to make sure that the required resolution is supported by both the monitor and the video adapter you are using.
Connector Video adapters are usually connected to the AGP connector on the motherboard; graphics adapters for PCI are less common - this is rather the province of older models of video adapters.
The video adapter communicates with the monitor via a special VGA or DVI interface (Figure 18).
Figure 16 – DVI and VGA connectors
VGA is an analog signal transmission interface, i.e. Control signals for three primary colors are transmitted, but each signal has 64 brightness levels. As a result, the number possible combinations(colors) increases to 262,144 (64 
). To create a realistic image using computer graphics color is often more important than high resolution, since the human eye perceives a picture with more color shades as more believable.
DVI is a digital signal transmission mode, i.e. the signal is converted to analog not when leaving the video adapter, but in the monitor itself. This is the advantage of DVI over VGA. A digital signal has only two discrete values: 1 and 0, i.e. every time you transfer a unit digitally, you receive exactly one unit. Regardless of voltage fluctuations or any interference occurring during transmission. In an analog system, as a result of transmitting a unit, you can no longer get a unit, but 0.935 or 1.062. Therefore, it is not necessary that you see on the screen exactly what the video card generates.
The main characteristics of the video adapter are: memory frequency, processor frequency, type of slot and connector for connecting to the monitor.