What is a VGA port (connector)? VGA connector: purpose, description, pinout

Our generation lives in the era of a scientific and technological revolution, but since we are “inside the process,” we do not notice the rapid change of generations of technical devices around us. If previously household appliances could serve for decades, now in two or three years they become hopelessly outdated - new ideas, new technologies and materials appear that allow these ideas to be implemented.

Since the creation of the first spark transmitters, radio-electronic equipment has been analog. However, after World War II, when the bipolar and field-effect transistor were invented and the first integrated circuits were developed, digital technology began to gain its place in the sun. From a circuit design point of view, digital equipment is more complex than analog equipment, but its functionality is much wider, and some of them are fundamentally unattainable with analog signal processing. Despite this, in the field of modern television technologies, analog video signals are used very widely and are not going to become a thing of the past.

The problem with the digital representation of a video signal is that the width of its spectrum is many times greater than the width of the spectrum of the same video signal, but in analog form. Modern digital television systems, which are gradually being switched to all over the world, are not capable of working with an uncompressed signal. It has to be encoded using the MPEG algorithm, which is known to be a lossy algorithm. So it turns out that despite the development and improvement of digital technologies, it is easier and cheaper to use analog video formats to transmit video signals over long distances: the signal spectrum width is quite acceptable, the equipment fleet is extensive, and the technologies have been developed to perfection.

Digital interfaces DVI and its development HDMI are, in general, interfaces of the near future, but they are intended to solve other problems.

The analog video signal used in modern television systems can be composite or component.

Composite CV(composite video) is the simplest type of analog video signal in which information about brightness, color and synchronization is transmitted in a mixed form. In the early stages of the development of video technology, it was the composite signal that was transmitted over a coaxial cable that connected VCRs or video players to televisions.

A more advanced version of the composite signal is the signal S-Video. This type of analog video signal provides separate transmission of the luminance (Y) signal and two combined chrominance (C) signals via independent cables, which is why this signal is also called YC. Because luma and chrominance signals are transmitted separately, S-Video occupies significantly more bandwidth than composite. Compared to a composite video signal, S-Video provides a noticeable gain in image clarity and stability, and to a lesser extent in color rendition. S-Video is widely used in semi-professional equipment, broadcast studios, and also when recording on 8 mm film in the Hi-8 standard from Sony.

These interfaces are not suitable for high-definition television and computer video because they do not provide the required image resolution.

Component video signals

To achieve maximum image quality and create video effects in professional equipment, the video signal is divided into several channels. For example, in an RGB system, the video signal is divided into red, blue and green components, as well as a sync signal. This signal is also called the RGBS signal; it is most widespread in Europe.

Depending on the method of transmitting synchronization signals, the RGB signal has several varieties. If the synchronization pulses are transmitted in the green channel, then the signal is called RGsB, and if the synchronization signal is transmitted in all color channels, then RsGsBs.

To connect the RGBS signal, use cables with four BNC connectors or a SCART connector.

RGBS video cable with BNC connectors.

SCART connector

Table 1. SCART connector pin assignments

The YUV system, which has become widespread in the United States, uses a different set of components: mixed luminance and synchronization signals, as well as red and blue color difference signals. Each component system requires a different type of equipment, and each has its own advantages and disadvantages. To connect devices of different video formats, special interface blocks are required. The connectors at the ends of the cables are usually RCA or BNC.

YUV component signal

RGBHV format component signal

The way a video signal is formed is as follows: the image is decomposed into signals of three primary colors: red (Red - R), green (Green - G) and blue (Blue - B) - hence the name “RGB”, to which horizontal and vertical synchronization signals are added ( HV), and then turns into an RGB signal with sync pulses in the green channel (RGsB), which is further converted into: a component (color difference) signal YUV, where Y=0.299R+0.5876G+0.114V; U=R–Y; V= B-Y, which is then converted into S-Video and composite video. The composite video signal is converted into an RF signal that combines audio and video signals. It is then modulated by a carrier frequency and turned into a broadcast television signal.

At the receiving side, the radio frequency signal is converted as a result of demodulation into a composite video signal, from which, in turn, as a result of a series of transformations, RGB and HV components are obtained.

The YPbPr component signal is converted to RGB + HV, bypassing many video circuits. Separating the Pb and Pr chrominance signals into separate channels significantly improves the phase accuracy of the color subcarrier, and color tone adjustment is not required.

High definition television signals (HDTV) 720p and 1080i are always transmitted in component format; HDTV in composite or s-video formats does not exist.

When the DVD format was born, it was decided that when digitizing material for recording on DVD, it was the component signal that would be converted into digital form and then processed using the MPEG-2 video data compression algorithm. The RGB signal output from a DVD player is derived from the YUV component signal.

It is important to note the difference between the ratio of color components in RGB and the component signal of the YUV format (YPbPr). In the RGB color space, the relative content (weight) of each color component is the same, whereas in YPbPr it takes into account the spectral sensitivity of the human eye.

Ratio of components in RGB color space

Component ratio in YPbPr color space

Limitations on the transmission distance of component types of video signals from signal sources to receivers are summarized in Table 2 (for comparison, some digital interfaces are also shown).

VGA video signals

One of the most common types of component signal is the VGA format.

The VGA (Video Graphics Array) format is a video signal format designed for output to computer monitors.

By resolution, VGA formats are usually classified according to the resolution of personal computer video cards that generate the corresponding video signals:

• VGA (640x480);
• SVGA (800x600);
• XGA (1024x780);
• SXGA (1280x1024);
• UXGA (1600x1200).

In each pair of numbers, the first shows the number of horizontal pixels, and the second shows the vertical number of the image.

The higher the resolution, the smaller the size of the luminous elements and the better the image on the screen. This should always be the goal, but as resolution increases, the cost of video cards and display devices increases.

Video technology is developing rapidly, and some computer formats such as MDA, CGA and EGA are a thing of the past. For example, the CGA format, which was considered the most common format for several years, provided an image with a resolution of only 320x200 with four colors!

The weakest video format currently in use, VGA, appeared in 1987. The number of gradations of each color in it is increased to 64, resulting in the number of possible colors being 643 = 262144, which is even more important for computer graphics than resolution.

The pin assignments of the VGA connector are shown in the table.

In addition to the video signals themselves (R, G, B, H and V), the connector (according to the VESA specification) also provides some additional signals.

The DDC (Display Data Channel) channel is designed to transmit a detailed “dossier” of the display to the processor, which, having familiarized itself with it, produces an optimal signal for a given display with the required resolution and screen proportions. This dossier, called EDID (Extended Display Identification Data), is a block of data with the following sections: brand name, model identification number, serial number, release date, screen size, supported resolutions and native screen resolution.

Thus, the table shows that if you do not use the DDC channel, then the VGA format signal is, in fact, a component RGBHV signal.

In professional equipment, instead of a D-Sub cable with a DB-15 connector, a cable with five BNC connectors is usually used, which provides better transmission line performance. Such a cable is better impedance-matched to the receiver and transmitter of the signal, has less crosstalk between channels, and is therefore better suited for transmitting high-resolution video signals (broad signal spectrum) over long distances.

VGA cable with DB-15 connector

VGA cable with five BNC connectors

Currently, the most widely used display devices are 4:3 aspect ratios: 800x600, 1024x768 and 1400x1050, but there are formats with unusual aspect ratios: 1152x970 (about 6:5) and 1280x1024 (5:4).

The rise of flat panels is pushing the market toward increased use of 16:9 widescreen displays with resolutions of 852x480 (plasma), 1280x768 (LCD), 1366x768 and 920x1080 (plasma and LCD).

The required link bandwidth for transmitting a VGA or video amplifier signal is determined as the product of the number of horizontal pixels times the number of vertical lines times the frame rate. The result obtained should be multiplied by a safety factor of 1.5.

W [Hz] = H * V * Frame * 1.5

The horizontal scanning frequency is the product of the number of lines (or rows of pixels) and the frame rate.

Thus, a UXGA signal requires a bandwidth of 173 MHz. This is a huge band: it extends from audio frequencies to the seventh television channel!

How to lengthen a component signal

In practice, there is often a need to transmit video signals over distances greater than those indicated in the above tables. A partial solution to the problem is to use high quality coaxial cables, with low ohmic resistance, well matched to the line, and with a low level of interference. Such cables are quite expensive and do not provide a complete solution to the problem.

If the signal receiver device is located at a considerable distance, you should use specialized equipment - so-called interface extenders. Devices of this class help eliminate the initial limitation on the length of the communication line between the computer and elements of the information network. VGA signal extenders operate at the hardware level, so they are free from any software compatibility, codec negotiation, or format conversion issues.

If we consider a passive line (i.e. a line without active terminal equipment), then an RG-59 cable is capable of transmitting composite video, a PAL or NTSC television signal without visible distortion on the screen only at 20-40 m (or up to 50-70 m via RG-11 cable). Specialized cables such as Belden 8281 or Belden 1694A will increase transmission range by approximately 50%.

For VGA, Super-VGA or XGA signals received from computer graphics cards, a regular VGA cable provides image transmission with a resolution of 640x480 over a distance of 5-7 m (and for resolutions of 1024x768 and higher, such a cable should not be longer than 3 m). High-quality industrial VGA/XGA cables provide a range of up to 10-15, rarely up to 30 m. In addition, the communication line will be subject to losses at high frequencies (High frequency loss), which manifests itself in a decrease in brightness until color disappears completely, deterioration of resolution and clarity.

To eliminate this problem, you can use a linear amplifier-corrector connected BEFORE the long cable. It uses a high-frequency loss compensation circuit called EQ (Cable Equalization) or HF (High Frequency) control. The EQ circuit provides frequency-dependent signal amplification to “straighten” the amplitude-frequency response (AFC). The general gain control allows you to counteract normal (ohmic) losses in the cable.

Such linear amplifiers allow (using cables of maximum quality) to transmit a signal with a resolution of up to 1600x1200 (60 Hz) over distances of up to 50-70 m (and more, with lower resolutions).

However, this is not always enough: sometimes long distances are needed, sometimes a long cable can induce interference that a linear amplifier cannot combat. In this case, the regular VGA coaxial cable can be replaced with another, more suitable media. Today, an inexpensive and convenient twisted pair cable is most often used for this, installing special converters (transmitter and receiver) at the ends of the cable.

The transmitting device of such an extender converts video signals into a differential symmetrical format, most suitable for twisted pair cables. On the receiving side, the standard video format is restored.

A regular Ethernet LAN cable, Category 5 and higher, is used. For video signals, unshielded cable (UTP) is best. Due to the low cost of such a cable, the entire signal transmission path usually does not increase in cost, despite the need to install additional devices.

This VGA signal extension method works well at distances up to 300 m.

Similar methods can be used to extend component signals of other types (YUV, RGBS, s-Video); the industry produces corresponding types of devices.

Note that VGA signal devices are usually well suited for transmitting YUV component video (and this is specified in their descriptions), if you use their R, G, B channels to transmit Y, U and V channels (H and V synchronization channels can be omitted use). Usually, it is enough to use adapter cables to match the type of connectors.

The transmission medium in extenders can also be optical fiber and wireless radio. Compared to twisted pairs, fiber optics will significantly increase the cost, and wireless communications will not provide sufficient noise immunity and reliability, and it is not easy to obtain permission to use it.

Good day.

One of the most common questions when connecting a monitor to a computer is understanding the variety of connectors and making the right choice of cable so that everything works (especially difficult if the monitor has several interfaces at once). Whether it was before, there is one VGA everywhere: everything is simple and clear. But over time (after the advent of high-resolution monitors), its capabilities became insufficient, and new interfaces began to come out...

In general, now you can most often find DVI, Display Port or HDMI interfaces on monitors. Moreover, they are all, in turn, divided into several more types (so to speak). The situation is even more complicated if the monitor has some interfaces and the PC has completely different ones. No wonder you get confused...

In this article I will try to sort out this whole tangle and answer typical and most common questions about this problem.

And so, closer to the point...

HDMI

One of the most popular and popular interfaces today. Found on the vast majority of laptops and computers (can also often be found on tablets). Suitable for connecting monitors, TV (and TV set-top boxes), projectors and other video equipment.

Peculiarities:

1. transmits both audio and video signals (simultaneously). In this regard, this is a big plus for the interface: no extra cables are needed to transmit the audio signal;
2. Full support for FullHD (1920x1080) resolution, with 3D effects. Maximum supported resolution up to 3840×2160 (4K);
3. the cable length can reach 10 meters, which is sufficient in most cases (with the use of repeater amplifiers - the cable length can be increased to 30 meters!);
4. has a throughput from 4.9 (HDMI 1.0) to 48 (HDMI 2.1) Gbit/s;
5. adapters from HDMI to DVI and vice versa are available for sale (very important for compatibility of old and new devices with each other);
6. HDMI has several types of connectors: HDMI (Type A), mini-HDMI (Type C), micro-HDMI (Type D) (see photo above). On laptops/PCs, the classic size type is most often used - HDMI (Type A). Micro and Mini are found in portable technology (tablets, for example).

If you have HDMI on your monitor and system unit (laptop), then the entire connection will boil down to purchasing an “HDMI-HDMI” cable (which can be bought at any computer store).

Please note that before connecting via HDMI, be sure to turn off both devices (PC and monitor). , if this is not done.

Display Port

A new interface that is quickly gaining popularity (a competitor to HDMI). Allows you to connect several monitors at once, supports 4K resolution, 3D image. There are two standard sizes: classic and Mini Display Port (the first option is found on regular laptops and monitors, see photo above).

Peculiarities:

1. both audio and video signals are transmitted simultaneously;
2. The maximum length of the Display Port cable can reach 15 meters;
3. data transfer speed up to 21.6 Gbit/s;
4. allows you to get a resolution of up to 3840 x 2400 at 60 Hz; or 2560 x 1600 pixels at 165 Hz; or you can connect two monitors at once with a resolution of 2560 x 1600 pixels and a frequency of 60 Hz.
5. Please note that in addition to the classic Display Port, there is another form factor: Mini Display Port.
6. By the way, the size of the Mini Display Port connector is about 10 times smaller than that of the DVI connector (about him later in the article)!
7. the interface has a small “latch” that securely fixes the cable when connected to the port.

DVI

This interface is almost 20 years old and still enjoys wide popularity (it was released in 1999). At one time, I seriously improved the quality of the image on the screen.

The maximum resolution is 1920 x 1080 pixels (however, some expensive video cards can transmit data in dual link mode and the resolution can reach 2560 x 1600 pixels).

Peculiarities:

1. Only the image is transmitted through the DVI connector (the audio signal will have to be transmitted via other channels);
2. resolution up to 1920×1200 pixels with cable length up to 10.5 m; resolution 1280×1024 pixels with cable length up to 18 m; in dual-channel data transfer mode - up to 2560 x 1600 pixels.
3. There are three types of DVI: DVI-A Single Link - analog transmission; DVI-I - analog and digital transmissions; DVI-D - digital transmission.
4. Various connectors and their configuration (DVI-A, DVI-D, DVI-I) are compatible with each other.
5. Please note that this standard is more likely to experience interference: for example, if there are other devices near the cable that emit an electromagnetic signal (telephone, printer, etc.). This can also happen due to poor cable shielding;
6. There are many adapters on sale from VGA to DVI and reverse;
7. The DVI connector is quite large, ~10 times larger than the Mini Display Port (Apple even released Mini DVI, but it was not very popular...).

VGA (D-Sub)

This standard was developed back in 1987. Despite this, it is still very popular and is used mainly for simple projectors, video set-top boxes, and small office monitors (where high resolution and very high-quality images are not required). Officially, resolutions of up to 1280×1024 pixels are supported, and therefore many are “prophesying” an imminent eclipse for this interface...

My personal opinion: many people “bury” this interface early, because thanks to hundreds of millions of devices that have been released over these 30 years, VGA will “outlive” some modern ones.

Peculiarities:

1. transmits only video signal (for audio it is necessary to use other channels);
2. maximum resolution up to 1280×1024 pixels, with a frame refresh rate of 75 Hz (in some cases it is possible to work at a higher resolution, but this is not officially guaranteed, and the image quality may deteriorate);
3. there are many VGA to HDMI, VGA to Display Port, VGA to DVI and reverse adapters;
4. Despite its “moral” obsolescence, the interface is supported by a variety of audio and video equipment, and is still in wide demand.

Popular questions about connecting and choosing a cable

Option 1: The monitor and computer have the same interface (HDMI or Display Port)

Perhaps this is the most favorable option. In general, it is enough to buy a standard HDMI cable (for example), connect devices using it and turn them on. No additional settings are required: the image is immediately displayed on the monitor.

Important!

Hot plugging HDMI may burn out the port! How to avoid this and what to do (if the monitor/TV via HDMI does not work) is described in this manual:

Option 2: devices have different interfaces. For example, on a laptop HDMI, on a VGA monitor.

This option is more complicated... In addition to the cable, you need to buy a special adapter (sometimes the cost of such adapters reaches 30% of the new monitor!). It is better to buy both the cable and the adapter as a set (from the same manufacturer).

Also keep in mind that older PCs/laptops with VGA|DVI connectors may simply not produce a high-resolution picture if you want to connect a large monitor/TV to them.

There are now quite a lot of adapters on sale that ensure the interaction of different interfaces with each other (VGA, Display Port, HDMI, DVI).

What if I take different versions of the HDMI connector?

If you mean form factor - i.e. Micro and classic size connectors, you need a special one to connect them. cable (possibly an adapter).

If we are talking about connecting a video card that supports the HDMI 1.4 standard (with 3D), say, to a monitor with HDMI 1.2, then the devices will work according to the HDMI 1.2 standard (without 3D support).

Does cable length matter? Which interface should you prefer?

Yes, cable length matters a lot. The longer the cable, the weaker the signal, the greater the likelihood of various interference, etc. Let's say, in the general case, it is undesirable for its length to exceed 1.5÷3 m.

Of course, the length is also affected by the interface you choose. For example, the HDMI interface allows you to use a cable up to 10 meters long (and with an amplifier up to 25-30!). While the same VGA cable, longer than 3 m, can significantly “spoil” the picture.

What about quality, today one of the best pictures is provided by HDMI and Display Port (resolution up to 4K, with simultaneous transmission of an audio signal, and with almost complete absence of interference).

Classic USB and USB Type C

By the way, on new laptops and PCs you can find USB Type C connector . Of course, it has not yet received widespread use, but it looks promising. Allows you to “hot” connect the monitor to a PC, simultaneously transmitting audio and video signals. In some cases, the monitor does not even require additional power - the power from the USB port is enough.

You might find this article useful on how to properly connect a monitor to a laptop (step by step instructions) -.

That's all for today, good luck everyone!

Every PC user sooner or later is faced with connecting his laptop or personal computer to a monitor using various cables and connectors. All of them differ from each other in structure, picture quality and maximum permissible cable length. In the 90s, a 15-pin VGA connector was used to connect CRT monitors, which produced a good image for that time. Over time, the resolution provided by VGA became insufficient and was replaced by a new 17 (17-29) pin DVI interface with the ability to display a much higher resolution due to its higher throughput.

DVI connector

To develop the Digital Visual Interface (DVI), large companies joined forces. It was jointly decided that it was inappropriate to convert the signal twice. As a result, the developers came to the decision to create a single digital interface that can display the original image without unnecessary changes or loss of quality.

Basic operating principle interface lies in the new technology of the TMDS data encoding protocol. Information previously implemented by the protocol is sequentially transmitted to the device.

The interface allows you to achieve a resolution of 1920x1080 at a frequency of 60 Hz. These parameters allow you to achieve throughput 1.65 Gb/s and this is using a single TMDS connection. If two connections are used, the speed will increase to 2 Gb/s. With such high performance, DVI is head and shoulders above its predecessors.

To explain to the average user why Digital Visual Interface is so good, we can only say that it is a digital video interface. It is not difficult to distinguish it from its analog predecessor - the connectors are always white, which makes it impossible to confuse it with others. The shape and a larger number of pins are also characteristic differences of the interface.

The interface cable is limited in length, like other connectors, its maximum length is no more than 10 m, which is 7 meters more than VGA.

Main types and differences

In addition to the characteristic differences from other interfaces, the Digital Visual Interface also differs from each other. The main differences between them are the number of channels and the ability to transmit an analog signal. Let's take a closer look at the popular variations:

The difference between the connectors can be summarized simply - the letter D indicates the presence of only a digital signal, the letter A indicates only an analog signal, the letter I indicates the presence of both types of signals.

In the case where the video card has a Digital Visual Interface output, but the monitor only has VGA, adapters are suitable. When purchasing adapters, you need to understand the difference between DVI-I and DVI-D; the former will be able to transmit the signal to VGA because there is an analog channel, but the second one does not have an analog communication channel and it will not be possible to transmit an image through it through an adapter; special expensive converters are used for this.

In addition to DVI-VGA and VGA-DVI adapters, there are other DVI-HDMI, HDMI-DVI, DVI-DisplayPort, DisplayPort-DVI, they all transmit a digital signal between themselves and there should be no connection problems.

Disadvantages of technology

The only significant drawback of the technology is cable length limitation. For example, when using a 15 m cable, the maximum resolution that can be achieved is 1280x1024, but if you use only a 5 meter cable, the resolution will increase to 1920x1200. If you need to connect a device over a long distance without losing the signal, you will have to use additional repeaters, which will strengthen the signal.

VGA connector

In 1987, Canon introduced the world to a new VGA (Video Graphics Array) connector, which was installed on the video card of the same name. The capabilities of the technology were more than enough, because the original resolution was 640x480. The maximum possible resolution without loss of image quality that Video Graphics Array is capable of producing is 1280x1024. Despite the fact that more efficient interfaces have long appeared and are pushing VGA out of the market, many TVs and video devices are still equipped with this connector. The reason for the displacement was the emergence of new monitors that require higher resolution.

The connector has a 15-pin wiring and is marked blue (with rare exceptions), which makes it easy to distinguish it from DVI (white). Maximum cable length connection is limited to 3 m.

Due to the development of technology, a new standard has emerged, Super Video Graphics Array or SVGA, which uses the same 15-pin connection as the Video Graphics Array but is significantly superior technically. The main difference between SVGA and VGA is number of colors displayed, there are 16 million of them in the new version of the interface, with 256 colors in the old one.

Main types

There are three main types of VGA connectors: DDC1, DDC2, E-DDC:

1. DDC1– allows the monitor to unilaterally transfer data with information about its characteristics to the computer. After which the video card determines this information on the cable and detects the DDC monitor connected to it
2. DDC2– a specification of this type allows for the exchange of information bilaterally. First, the monitor transmits its data to the computer, after which the computer adjusts the necessary parameters to the connected monitor.
3. E-DDC– represents the most effective specification. Information about the data of the connected monitor was saved in the device memory.

All 15 contacts are arranged in 3 rows of 5 contacts. First three contacts are responsible for transmitting analog video signals of three different colors (1,2,3). Each of them has its own land- 6,7,8 respectively. Pins 13 and 14 are responsible for horizontal and vertical synchronization. In addition to transmitting a video signal, the interface has two-way communication with the monitor.

Interface pinout:

If we are talking about a mini VGA connector (a smaller analogue with the same parameters), then the pinout will be as follows:

Extension Cords

There are situations when the computer and the connected monitor or TV are in different rooms and connecting them will require a cable of non-standard length. You can buy it at any computer store, but there are two problems:

• too much high price cable - from $20 for 15 meters;
• rigidity standard cable, which becomes a big problem for beautiful and correct installation in skirting boards. If, when installing the cable, you need to go through the wall, then the factory cable will obviously not help because... you will have to drill a hole with a diameter of 40 mm.

In such cases, the ideal solution would be to make an extension cord yourself. An ordinary twisted pair cable of category 5 or 6 will come to the rescue with this.

In terms of price, it significantly outperforms the factory Video Graphics Array extension cord; its price is about 15 rubles per meter, and its diameter is only 8 mm.

Using only 8 twisted pair pins, you can easily solder an extension cord, but you can do it even easier by purchasing a VGA to RJ-45 adapter at the store.

DIY DVI-D to VGA adapter

It is impossible to find such an adapter. The reason for this is that technologies use different ports and data types. If you look closely at the DVI-D pinout, you will notice that it no contacts to transmit the analog signal that VGA requires.

In this case it may help converter DVI-D – VGA, which converts the digital signal coming from the Digital Visual Interface into analog. This is the only connection option.

Worth noting, that if you break out 4 “extra contacts” due to which a regular adapter cannot be inserted into the connector, then nothing will work anyway, since they are the ones responsible for transmitting the analog signal.

Maximum cable length

All interfaces have a limitation on the maximum permissible cable length without losing signal quality. The longer the cable, the worse the signal, and, accordingly, the maximum resolution. The maximum length is different for each type, since the interfaces use different technologies and types of signals.

For DVI – 10, VGA – 3 m, HDMI – 10 m.

The difference between DVI and VGA

The main difference between these connectors is maximum resolution And picture quality. In addition, the Digital Visual Interface has from 17 to 29 pins, while VGA has only 15. Another difference is the type of signals with which the interfaces work: for VGA it is analog, and for Digital Visual Interface it is digital. It is for this reason that VGA has to do the conversion twice, which significantly degrades the quality of the resulting image.

Which is better DVI or HDMI

In comparing these two interfaces, we can say that they are somewhat equivalent. The big advantage of HDMI is that with just one cable you can transmit both video and audio data, thereby reducing the number of wires that are abundant in modern multimedia systems. The significant difference is maximum resolution, which for HDMI can currently be 10240 × 5760.

Difference between VGA and HDMI

It is incorrect to compare these two interfaces due to their difference in creation time. HDMI is a fairly new connector that provides the user with an excellent picture and excellent sound in just one cable. Video Graphics Array is now used mostly in old technology that is not compatible with new technologies.

We select the required plug for the appropriate connector. What types of cables do manufacturers offer? "HDMI,DVI,VGA,DisplayPort" and which interface is optimal for connecting a monitor.

Previously, to connect a monitor to a computer, only an analog interface was used VGA. Modern devices have connectors "HDMI,DVI,VGA,DisplayPort". Let's see what advantages and disadvantages each of the interfaces has.

With the development of new technologies for flat-panel monitors, the connector capabilities have become insufficient VGA. To achieve the highest image quality, it is necessary to use a digital standard such as DVI. Home entertainment device manufacturers have created a standard HDMI, which became the digital successor to the analog Scan connector. Somewhat later, VESA (Video Electronics Standards Association) developed DisplayPort.

Main interfaces for connecting monitors.

■ VGA. The first connection standard, still in use today, was developed in 1987 by the then leading computer manufacturer IBM for its PS/2 series PCs. VGA is an abbreviation for Video Graphics Array (an array of pixels), at one time this was the name of the video card in PS/2 computers, the resolution of which was 640x480 pixels (the combination “VGA resolution” often found in technical literature means exactly this value).

An analog data transmission system with increasing resolution only worsens the picture quality. Therefore, in modern computers the digital interface is the standard.

. ■ DVI. This abbreviation is oz-naHaeTDigital Visual Interface - digital video interface. It transmits the video signal in digital format while maintaining high image quality.

DVI is backwards compatible: Almost all computers have a DVI-I connector, which is capable of transmitting both digital video data and a VGA signal.

Inexpensive video cards are equipped with a DVI output in the Single Link modification (single-channel solution). The maximum resolution in this case is 1920x 1080 pixels. (Full HD). More expensive video card models have a two-channel DVI (Dual Link) interface. They can be connected to monitors with a resolution of up to 2560x1600 pix.

The DVI connector is large enough that Apple has developed a Mini DVI interface for its laptops. Using the adapter, you can connect devices with Mini DVI to monitors equipped with a DVI connector.

connection interfaces

■ HDMI. The abbreviation HDMI stands for High Definition Multimedia Interface, that is, a high-definition multimedia interface. In modern home entertainment devices such as flat-screen TVs and Blu-ray players, HDMI is the standard connection interface.

As with DVI, the signal is transmitted in a digital format, which means the original quality is preserved. Together with HDMI, HDCP (High Bandwidth Digital Content Protection) protection technology was developed, which prevents the creation of exact copies, for example, of video materials.

The first devices with HDMI support appeared at the end of 2003. Since then, the standard has been modified several times, in particular, support for new audio and video formats has been added (see table above).

For miniature models of equipment there is a Mini HDMI interface; A matching HDMI/Mini HMDI cable is included with many devices.

■ DisplayPort(DP). A new type of digital interface for connecting video cards with display devices is intended to replace DVI. The current version of the standard 1.2 allows you to connect multiple monitors when they are daisy-chained into one chain. However, currently there are not many devices with a DP port. Being a direct competitor to HDMI, this interface has a significant advantage from the point of view of manufacturers: it does not require licensing fees. While for each device with HDMI you have to pay four American cents. If the connector on a computer or laptop is marked “DP++”, this indicates that the adapter can be used to connect monitors with DVI and HDMI interfaces.

To ensure that there is enough space on the back of modern video cards for connectors for other purposes, a smaller version of the DP interface was developed. For example, Radeon HD6800 series video cards contain up to six Mini DP ports.

HDMI,DVI,VGA,DisplayPort

Which of these standards will be most widely adopted? HDMI has a very high chance of success, since most devices have this interface. However, there is a new trump card in the deck of Asian manufacturers: according to official data, the Digital Interactive Interface for Video and Audio (DiiVA) provides a throughput of 13.5 Gbps (DP: 21.6; HDMI: 10.21. In addition, as the companies promise, the maximum cable length between devices, such as a Blu-ray player and a TV, will be up to 25 m. There is no information yet on what the DiiVA interface looks like.

Transfer video via USB

Two years ago it became possible to connect monitors via USB using DisplayLink adapters. However, due to the low (480 Mbps) bandwidth, the USB 2.0 connection is not suitable for video transmission. Another thing is the latest version of the USB standard (3.0), providing data transfer speeds of up to 5 Gbit/s.
An adapter from DisplayLink allows you to connect monitors directly to a computer's USB port.

How to connect a computer and a monitor with different interfaces.

Thanks to adapters, there are many connection options (see table below).

Common adapters, such as DVI-I/VGA, are quite reasonably priced. So-called converters that convert the digital DisplayPort output signal into an analog VGA signal are much more expensive.

However, for example, when connecting a TV with an HDMI interface to the DVI connector, there is almost always no sound.

Is it possible to combine devices with different HDMI versions?

With this combination, only the functions of the earlier version of the corresponding interface will be available. For example, if a video card with HDMI 1.2 is connected to a 3D TV that supports HDMI 1.4, then 3D games will only be displayed in 2D format.
Advice. Installing a new driver allows you to add support for HDMI 1.4 in some video cards based on NVIDIA chips, for example GeForce GTX 460.
Which connectors provide the best picture quality?

Testing has shown that the analog VGA interface provides the worst image quality, especially when transmitting signals with a resolution of more than 1024x768 pix. Even 17-inch monitors support this resolution today. Owners of monitors with a larger diagonal and a resolution of 1920x1080 pixel are strongly recommended to use DVI, HDMI or DP.

How to connect a monitor to a laptop?

Most laptops are equipped with connectors for connecting external monitors. First, connect the monitor to the laptop. After that, using the buttons Ш and KPI, you can switch between the following modes.

■ Using an external monitor as the main one. The laptop display turns off and the image is displayed only on the connected external monitor. The best option for movie buffs and gamers.

Clone mode. External monitor and laptop display show the same image

■ Practical for presentations and seminars.

■ Multi-screen mode. Allows you to increase the size of your Windows desktop by using multiple monitors. It is very convenient, for example, when typing text in Word, to have email messages in front of your eyes.

Will it be possible to connect the TV to the computer?

Modern computers and laptops do not have analog video interfaces such as S-Video or a composite connector. Therefore, you definitely won’t be able to connect an old CRT TV. However, the vast majority of flat-panel models are equipped with DVI or HDMI interfaces, which means connecting them to a computer is not difficult.

Netbooks, as a rule, only have a VGA output, and only those TVs that have a VGA input can be connected to them.

Is it possible to connect a monitor via USB

For traditional monitors this is only possible using an optional DisplayLink adapter. However, there are also models on sale that connect directly to a computer’s USB port - for example, Samsung SyncMaster 940 UX.

What is the maximum monitor cable length?

Cable capabilities depend on the connection type. When using DVI, the connection length can reach 10 m, but in the case of HDMI and VGA it should not exceed 5 m. To achieve maximum transfer speed.

What should you pay attention to when purchasing a video cable?

To prevent nearby electronic devices from affecting the quality of the transmitted signal, purchase only well-shielded cables. When using a low-quality cable, other devices may cause interference and in some cases even reduce the data transfer rate. As a result, the screen will display a choppy image or an aliasing effect will appear. Gold-plated contacts prevent corrosion of the plugs due to high air humidity. In addition, the gold-plated contacts used in modern cables reduce the resistance between the connector and the plug, which improves transmission quality. But as you can see from practice: you can forget about all this, gold-plated contacts and other nonsense, with cheap cables made in China, namely, they are supplied complete with monitors and video cards. And they cope with their responsibilities very well.

For reference: once somewhere they gathered music lovers to test cables. There were both gold-plated and platinum contacts, from $1000 per cord and much more. Well, the ratings were given for sound quality. To determine the winner, the competition was held naturally in the dark, the manufacturer was not visible. Well, one of the organizers came up with the idea of ​​sending a signal through an ordinary iron crowbar (which is used to hammer the ground). And what do YOU ​​think, he took one of the prizes.

And music lovers spent a long time explaining what crystal clear sound comes through this cool cable. So turn on your head, otherwise I saw the guys have a cable DVI at a price higher than the video card and monitor combined.

Most LCD and plasma TVs have a VGA connector, or as it is also called, D-sub. In addition, it is used to connect the system unit and the monitor. The abbreviation VGA comes from the name of computer video adapters. The VGA connector is designed by Canon. At first it was the smallest compared to other similar connectors.

general information

VGA connector: pinout

So, we present to your attention the wiring of such a connector, and at the same time we will decipher the purpose of each pin:

1. Red channel - 75 Ohm, 0.7V.

2. Green channel - 75 Ohm, 0.7V.

3. Blue channel -75 Ohm, 0.7V.

4. Second identification bit.

5. Common wire.

6. "Ground" of the red channel.

7. "Earth" of the green channel.

8. "Earth" of the blue channel.

10. "Ground" synchronization.

11. Zero identification bit.

12. Single identification bit, or DDC data.

13. Composite or line synchronization.

14. Frame synchronization.

15. DDC clock, or third identification bit.

Conclusion

It should be noted that audio information is not transmitted through the mentioned type of connection. This may cause additional difficulties in synchronizing sound and video. After all, TVs usually do not have additional audio inputs compatible with the VGA connector. The easiest way to synchronize two signals is to use a separate