Types of Computer Ports
With the advancement of technology, display signal transmission and display effect are constantly improving. Usually, a display has multiple transmission signal interfaces, and different signal interfaces have different transmission advantages and disadvantages. Let's gain a preliminary understanding of the various signal interfaces.
There are four main types of display interfaces on the market: HDMI, VGA, DP, and DVI. The appearance and shape of these four interfaces are also different. When building a computer, we need to consider the matching of the host graphics card interface and the display interface. Now, public graphics cards will come with HDMI and DP interfaces. Some manufacturers will add a DVI interface to the graphics card according to market demand, because the VGA interface transmits analog signals, and data will be lost during the transmission process, so the mainstream has gradually abandoned it.
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DVI Port
The full name of DVI is Digital Visual Interface. It was formed by Silicon Image, Intel (Intel), Compaq (Compaq), IBM, HP (Hewlett-Packard), NEC, Fujitsu (Fujitsu) and other companies in 1999 to establish DDWG (Digital Display Working Group, Digital Display Working Group) interface standard. It is based on Silicon Image's PanalLink interface technology, and takes the TMDS (Transition Minimized Differential Signaling, minimized transmission differential signal) electronic protocol as its basic electrical connection. TMDS is a differential signaling mechanism that encodes pixel data and transmits it over a serial link. The digital signal generated by the graphics card is encoded by the transmitter according to the TMDS protocol, then sent to the receiver through the TMDS channel, and sent to the digital display device after decoding. A DVI display system is composed of a transmitter and a receiver. The transmitter is the source of the signal, which can be built into the graphics card chip or appear in the form of an additional chip on the graphics card board; while the receiver is a circuit on the display that can receive, decode and transmit digital signals. In the digital display circuit, the signal sent by the graphics card passes through both to the picture on the monitor.
Because this interface was released relatively early, it is mainly used for PCs, and the compatibility with TV signals is relatively poor. It can only support 8-bit RGB signal transmission. Although too many pins support analog devices, they also form an oversized interface. fact. This interface has three different interface forms: DVI-A, DVI-D, and DVI-I. Among them, DVI-D only has a digital interface, and DVI-I has digital and analog interfaces.
The DVI-D interface is a digital signal interface in the true sense, and it is also divided into single-channel and dual-channel, that is, the interface is 18-pin or 24-pin. Among them, the 24-pin interface can transmit more data and supports 3D screen display, with a maximum resolution of 1080P.
Since the DVI interface avoids the frequent conversion between digital signals and analog signals during the video signal transmission process between the computer and the monitor, compared with the VGA interface, the DVI interface can display image details better.
However, this interface only exists in PC computers and cannot be applied to game consoles, disc players, flat-panel TVs and other equipment.
In addition, this interface can only transmit video signals, and has a large volume. Due to problems such as poor compatibility, inconvenient use, and low transmission bandwidth, this interface has gradually been eliminated by the market.
VGA Port
The full name of VGA is Video Graphics Array, which is a display standard proposed by IBM in the 1980s. The interface has a total of 15 pins and is divided into three rows. Because VAG transmits analog signals for red, green, and blue, it cannot be found on mainstream graphics cards. Since some old monitors and projectors also have VGA ports, you can attach adapters to realize signal transmission
The information processed by the graphics card is eventually output to the monitor. The output interface of the graphics card is the bridge between the computer and the monitor, and is responsible for outputting corresponding image signals to the monitor. CRT monitors, due to design and manufacturing reasons, can only accept analog signal input, which requires the graphics card to have the ability to output analog signals. The VGA interface is the interface for outputting analog signals on the graphics card. The VGA (Video Graphics Array) interface is also called D-Sub interface. Although LCD monitors can directly receive digital signals, many low-end products use VGA interfaces to match graphics cards with VGA interfaces. The VGA interface is a D-type interface, with a total of 15 pins, divided into three rows, five in each row. The VGA interface is the most widely used interface type on graphics cards, and most graphics cards have this type of interface. Some graphics cards without a VGA interface but with a DVI interface can also convert the DVI interface into a VGA interface through a simple adapter. Usually, graphics cards without a VGA interface will come with such an adapter.
HDMI Port
The full name of HDMI is High Definition Multimedia Interface, an interface that can send fully digital video and audio at the same time; it is especially suitable for connecting to a TV, and has strong anti-interference. The current highest HDMI 2.1 standard can support 8K 60Hz and 4K 120Hz, and the highest resolution can reach 10K; in addition, the HDMI interface high dynamic range HDR bandwidth can reach 48Gbps.
In April 2002, seven companies including Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson, and Toshiba formed the HDMI organization and began to formulate new standards for digital video/audio transmission. By the end of 2002, the HDMI 1.0 standard (High-Definition Digital Multimedia Interface) (HDMI) was proclaimed, and version 1.3 was proclaimed by the end of 2006. The most important change is to further increase the bandwidth to transmit higher resolution and color depth. HDMI is compatible with DVI on the pin, but uses a different package. Compared with DVI, HDMI can transmit digital audio signals, increase support for HDCP, and provide better optional DDC functions. HDMI supports a data transmission rate of 5Gbps, and can be transmitted up to 15 meters, which is enough to handle a 1080P video and an 8-channel audio signal. Our HDMI monitor deliver vivid image quality through the HDMI port.
Display Port
DisplayPort is also a high-definition digital display interface standard that can be connected to a computer and a monitor, or to a computer and a home theater. In May 2006, the Video Electronics Standards Association (VESA) confirmed version 1.0 of the standard, and updated to version 1.1 half a year later, adding support for HDCP. Version 2.0 is also expected to be released this year. As a competitor of HDMI and UDI and a potential successor to DVI, DisplayPort has won the support of industry giants such as AMD, Intel, NVIDIA, Dell, HP, Lenovo, Philips, Samsung, etc., and it is free to use, unlike HDMI. High licensing fees. AMD's roadmap shows that it will start supporting DisplayPort by the end of this year and early next year to replace HDMI.
In terms of performance, DisplayPort 1.1 supports a maximum transmission bandwidth of 10.8Gbps, while the latest HDMI 1.3 standard can only support a bandwidth of 10.2G/s; in addition, DisplayPort supports WQXGA+ (2560 × 1600), QXGA (2048 × 1536) and other resolutions and 30/36-bit (10/12-bit per primary color) color depth, 1920 × 1200 resolution, color support up to 120/24-bit, ultra-high bandwidth and resolution are completely sufficient to adapt to the development of display devices. Our Displayport monitor with 16.7M color depth and 100% sRGB color gamut, display rich colors and vivid images through the display port.
This interface is a display interface released by the Video Electronics Standards Association (VESA). It supports 8-bit and 10-bit colors. It has been updated to version 1.4. It can transmit 10-bit 4K 120Hz video and also supports 8K 60Hz video. It is also the mainstream interface for monitors. At the same time, DP1.4 is compatible with the USB Type-C interface. This interface can transmit data and transmit audio and video signals at the same time.
This makes the user’s operation more convenient, which is why displays such as the current Philips 279C9, AOC U27U2, and BenQ EW2780U choose to be equipped with a Type-C interface to enhance the user experience.
As an enhanced version of HDMI, DP provides support for high-definition audio signal transmission while transmitting video signals, and also supports higher resolution and refresh rate. When using 4K resolution, due to insufficient HDMI bandwidth, only up to 30 frames can be transmitted, and the DP interface is fully functional.
USB-C Port
Universal Serial Bus (English: Universal Serial Bus, abbreviation: USB) is a serial bus standard and an input-output interface technical specification. It is widely used in information communication products such as personal computers and mobile devices, and has extended to photographic equipment, digital TV (set-top box), game consoles and other related fields. The latest generation is USB4, with a transmission speed of 40Gbps, three levels of voltage 5V/12V/20V, and a maximum power supply of 100W. The new Type-C interface achieves positive and negative blind insertion.
The USB interface is divided into three types: standard USB interface, Mini USB interface and Micro USB interface.
1. Standard USB interface
It is divided into two types: Type-A and Type-B. The Type-A interface is also the most commonly used USB interface in our daily life. It is widely used in mice, keyboards, U-disk and other equipment. Type B is widely used in printers. , special monitors and other equipment.
2. Mini USB interface
The Mini USB interface is a small USB interface. Its indicators are the same as standard USB, but ID pins (used to distinguish whether the device is a host or a peripheral) have been added to realize OTG (On The Go, With this function, you can realize data transmission between devices in the case of the device.
Due to its relatively small size, the Mini USB interface is common on some small devices, such as MP3, MP4, radio, etc., and some types of mobile phones also use this interface.
3. Micro USB interface
The Micro USB interface is the next-generation interface of Mini USB. The plug of the Micro USB interface is made of stainless steel, and the plugging life is increased to 10,000 times. Compared with the Mini USB interface, the height is reduced by half while the width is almost unchanged. Smaller.
Type-C is a brand-new USB interface form, which is developed with the latest USB 3.1 standard. It was released by the USB-IF organization in August 2014, and it is a brand-new interface developed by the USB standardization organization to solve the long-term inconsistencies in the physical interface specifications of the USB interface, and the power can only be transmitted in one direction. It integrates charging, display, and data transmission. All in one. The biggest feature of the Type-C interface is that it supports two-way insertion, which officially solves the global problem of "USB can never be inserted correctly", and it can be inserted at will.
The TYPE-C hardware interface has obvious characteristics, mainly as follows:
(1) Supports positive and negative symmetrical insertion to solve the problem that the reverse plug cannot be inserted in practical applications;
(2) The interface is slender, which can support thinner and lighter devices, and make the design of portable devices thinner and smaller;
(3) Supports higher power transmission, up to 100 watts, and supports more high-power load devices;
(4) Supports flexible single-port and dual-port TYPE-C applications;
(5) Supports bidirectional power transmission, both for power transmission and power reception.
Conclusion
Currently, the interface with the best performance on the market is DisplayPort, followed by the HDMI interface. The DVI interface and VGA interface are still in use but are gradually being replaced.
The VGA interface, also known as the D-Sub interface, uses analog signals and is limited to video transmission. The DVI interface supports both analog and digital signal transmission. Its obvious drawback is that it does not support audio signals. The HDMI 1.4 interface is currently the most widely used on monitors. It supports multi-channel audio transmission, can provide realistic colors, and supports 4K resolution, but the refresh rate is only up to 30 Hz. HDMI 2.0 further expands the color depth and supports 4K at a 60 Hz refresh rate. Both versions 1.4 and 2.0 support Adaptive Sync, which is AMD FreeSync technology. HDMI 2.1 brings support for Dynamic HDR, 4K at 4K and 8K at 120 Hz. The DP interface is also a high-definition digital display interface standard, which is currently the mainstream. It is used in some high-end displays and can be regarded as an updated version of the HDMI interface. When you use a 4K display, the HDMI bandwidth is not enough, and it can only transmit 30 frames. DP is more than capable.
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