What is DVI?
DVI (Digital Visual Interface) stands for Digital Visual Interface. It is a digital video interface standard used to connect digital display devices and computers, such as LCD monitors and computer graphics cards. DVI was developed as the successor to VGA (Video Graphics Array) and provides higher quality and clearer digital video signals. It is widely used in desktop computers, laptops, and high-definition televisions, among other devices.
DVI supports both digital and analog signals, depending on the specific DVI type and the capabilities of the connected devices. It allows for the transmission of high-resolution video content, making it popular in applications where image quality is crucial, such as graphic design, gaming, and multimedia production.
ADVANTAGES OF DVI
The DVI interface can provide higher resolutions than VGA, thus delivering better image quality. When a computer needs to connect to a digital display, the DVI interface is the preferred transmission interface. Additionally, the DVI interface can also transmit audio signals and composite video signals.
DVI types
Nowadays, when people purchase LCD monitors, they generally understand that it is best to buy models with DVI interfaces. However, even though they are all called DVI, there are actually different types, and each type has different functionalities. The DVI interface is mainly divided into three types: DVI-A, DVI-D, and DVI-I.
DVI-A stands for DVI-Analog. DVI-A is essentially the DVI representation of VGA. Therefore, the DVI-A interface can only transmit analog signals and is suitable for older CRT monitors, which have gradually been phased out. The mainstream DVI used in current LCD monitors is generally not DVI-A. Standard VGA cables can be used with a DVI-A to VGA adapter for DVI-A connections.
DVI-A
DVI-D stands for DVI-Digital. DVI-D can only transmit digital signals and is suitable for digital displays such as LCD monitors, projectors, and high-definition TVs. This interface does not support analog signals and cannot be used to connect older CRT monitors. DVI-D can only receive signals from DVI-D interfaces.
DVI-I stands for DVI-Integrated. Compared to the purely digital interfaces like DVI-A and DVI-D that only support analog or digital signals respectively, DVI-I can transmit both analog and digital signals. It can be considered as a combination of DVI-A and DVI-D. When using this interface, digital signals are prioritized for transmission, and if digital signal transmission is not possible, the interface switches to analog mode.
DVI cable types
DVI-D Single-Link Cable:
Description: This cable supports digital signals and is suitable for DVI-D Single-Link interfaces.
Features: It consists of 18 pins and can transmit digital video signals with a maximum resolution of 1920x1200 pixels at a frequency of 60Hz.
DVI-D Single-Link
DVI-D Dual-Link Cable:
Description: This cable also supports digital signals but is designed for DVI-D Dual-Link interfaces.
Features: It has 24 pins, providing higher bandwidth and allowing for higher resolutions and refresh rates compared to DVI-D Single-Link cables. It can support resolutions up to 2560x1600 pixels at 60Hz.
DVI-D Dual-Link
DVI-I Single-Link Cable:
Description: The DVI-I Single-Link Cable is used to connect devices that support the Single-Link DVI-I interface.
Features: It consists of 18 pins and is capable of transmitting both digital and analog signals. The DVI-I Single-Link Cable can transmit video signals with a maximum resolution of 1920x1200 pixels and a refresh rate of 60Hz.
DVI-I Single-Link
DVI-I Dual-Link Cable：
Description: The DVI-I Dual-Link Cable is used to connect devices that support the Dual-Link DVI-I interface.
Features: It consists of 24 pins, providing higher bandwidth compared to the DVI-I Single-Link Cable. The DVI-I Dual-Link Cable can support higher resolutions and refresh rates, such as video signals with a maximum resolution of 2560x1600 pixels and a refresh rate of 60Hz.
DVI-I Dual-Link
It is worth noting that the mentioned DVI cable types are specific to DVI interface types (DVI-D and DVI-I). The DVI-A interface only supports analog signals and does not have specific cable types.
ALSO READ: Graphics Card Explained: Classification, Working and Structure
How To Choose The Right DVI cable types
When choosing a DVI cable, make sure it matches the DVI interface type supported by your devices. For example, if your source device and display device both have DVI-D dual-link ports, you should use a DVI-D dual-link cable to take advantage of its higher bandwidth capabilities. Additionally, consider factors such as cable length, build quality, and shielding to ensure optimal signal quality and reliability.
Single-link DVI vs dual-link DVI
The difference between single-link DVI and dual-link DVI is the number of conductors used for signal transmission. Dual-link DVI has more conductors compared to single-link DVI. Single-link DVI supports a maximum bandwidth of 165 MHz (1920 x 1080 @ 60 Hz, 1280 x 1024 @ 85 Hz) and has only 18 pins available for transmission. Dual-link DVI has 24 pins in the connector for signal transmission and supports a maximum bandwidth of 2x165 MHz (2048 x 1536 @ 60 Hz, 1920 x 1080 @ 85 Hz).
In general, for resolutions up to 1920x1200, both single-link and dual-link DVI interfaces provide the same image quality.
Why DVI
Why do some low-end graphics cards still retain different DVI interfaces?
In fact, the DVI interface, especially the DVI-I interface in dual-link mode, has performance comparable to the first-generation HDMI and can already meet the high refresh rate scenarios at 1080P. However, it has one drawback, which is the inability to transmit audio signals. Additionally, its larger physical size and lack of iterations led to its defeat against HDMI, which underwent multiple iterations, and the emerging DisplayPort (DP).
However, its powerful compatibility ensures that it can still serve many "high-end" monitors from the past, allowing these monitors to continue to be used in areas such as stock trading, industrial control, office work, and design, thus extending their usability. This is why, to this day, the DVI interface and graphics cards that use it have not been completely phased out.
DVI vs HDMI vs VGA vs DP
VGA Interface:
Let's start with the oldest VGA (Video Graphics Array) interface, which was introduced in 1987 and initially used for CRT monitors. Since early devices were analog, VGA also employed an analog protocol. Its theoretical resolution can reach up to 2048x1536, but analog signals have weak resistance to interference. The maximum supported resolution for VGA cables in the market is typically 1080p/60Hz. These parameters are clearly insufficient to meet today's requirements, and VGA lacks the ability to transmit audio and support hot-plugging, which are obvious disadvantages. As a result, VGA is not commonly seen in the consumer market anymore. However, it is still used in some industrial equipment, medical devices, radar recorders, and older projectors that do not require frequent upgrades.
DVI Interface:
If you see a cable that needs to be fastened with screws on your desktop computer, it's likely a DVI cable. DVI can transmit digital signals (analog as well) and has strong anti-interference capabilities. It achieves higher resolutions and comes in various interface types. Initially, these different specifications were meant to simplify the cumbersome conversion between digital and analog signals. However, today, if there are no special requirements, the DVI cables available in the market are mostly of the highest specifications.
HDMI Interface:
HDMI shares the same core technology (TMDS) as DVI, but the cables are smaller, it can transmit audio, offers better picture quality, and is compatible with DVI. There are three types of HDMI interfaces available on the market, suitable for regular devices, portable devices, cameras, game consoles, and more. HDMI has become the most widely used display interface, and it has evolved with different versions that support increasingly higher resolutions and refresh rates. However, HDMI's compatibility is considered somewhat limited in professional fields, and the use of HDMI requires licensing fees.
DP Interface:
The latest DP (DisplayPort) interface is the biggest competitor to HDMI. DP transmits video content in the form of data packets and allows the monitor to adapt to the frame rate of the graphics card to avoid screen tearing (G-SYNC technology). It also enables daisy-chaining multiple monitors with a single DP cable (Multi-Stream Transport technology). DP has not achieved the same level of popularity as HDMI, and currently, only devices with high demands for high-resolution and high-refresh-rate support tend to have DP interfaces. However, due to its powerful performance and completely free usage, DP is expected to have greater application potential in computer displays in the future.
3 FAQ with DVI
Q: Is DVI stronger than HDMI?
A: DVI and HDMI offer comparable signal quality. DVI is video-only and bulkier, supporting higher resolutions and refresh rates. HDMI is versatile, supporting both video and audio, with smaller cables and compatibility with consumer electronics devices. The choice depends on your specific needs: HDMI for audio, convenience, and compatibility, and DVI for higher resolutions and video-only transmission.
Q: Can I plug a DVI-D into a DVI-I?
A: Yes, you can plug a DVI-D (digital-only) cable into a DVI-I (integrated digital and analog) port. The DVI-I port is designed to support both digital and analog signals, so it is compatible with DVI-D cables, which carry only digital signals. However, keep in mind that if you connect a DVI-D cable to a DVI-I port, you will only be able to transmit a digital signal, and any analog capabilities of the DVI-I port will not be utilized.
Q: Is DVI outdated?
A: DVI can be considered somewhat outdated in comparison to newer display interfaces like HDMI and DisplayPort. While DVI still has its uses, such as compatibility with older monitors and certain industrial applications, it lacks features like audio transmission and support for higher resolutions and refresh rates. HDMI and DisplayPort have become more prevalent in consumer electronics and offer improved performance and versatility. However, DVI is still found in some devices and can be a viable option depending on specific requirements or the need to connect to legacy hardware.
