What is DVI?
DVI (Digital Video Interface) is an interface and transmits analog and digital image signals from a computer to a flat screen. It replaces the old VGA interface. This had the disadvantage that analog signals lose quality with longer or inferior connection cables, resulting in reduced image quality. DVI has the advantage that digital image signals from the graphics card do not have to be converted into analog image signals, as is the case with VGA. With DVI, it was possible for the first time to route the digital image signal directly to the digital flat screen without any loss of quality. With DVI, the image data retain their digital character throughout the entire signal chain and thus remain unaltered. This has enabled DVI to hold its own against analog interfaces such as VGA with better image quality. The success of the DVI standard in the computer sector was due to its ease of use and good image quality. DVI also allows components to be connected and disconnected on the fly. This advantage makes sense when you want to replace mobile devices, such as laptops, monitors or beamers, without having to turn them off.
DVI or HDMI - the most important differences
Even though DVI connections are more and more replaced by HDMI connections, you can still find them. Especially if you are a hobbyist and deal with older devices, you will come across DVI again and again. Therefore, here is a short excursion to the advantages and disadvantages of the two connection types.
- HDMI transmits picture and sound signals in parallel. DVI can only transmit the image signal.
- If the PC is to be connected to the monitor via DVI, the appropriate audio cable is required.
- HDMI can transmit 4K or 8K, which DVI cannot.
- HDMI is suitable for home theater sound with up to six channels and 5.1 surround sound setups.
- DVI no longer plays a role in home entertainment, but is most likely used to connect a graphics card on the computer to the PC.
- The picture quality does not differ between DVI and HDMI if the signal is transmitted without interference.
- HDMI always supports HDCP (Digital Copy Protection), DVI supports HDCP only sometimes.
- If a DVI cable does not support HDCP, you will not see a picture on blurays or DVDs.
Which cable lengths are possible?
The maximum possible cable length when connecting a monitor via DVI depends on the resistance of the connecting cable as well as the quality of the signal amplification. As a rule, you are on the safe side with all lengths up to 5 meters. However, more than 10 meters should not be exceeded between two cable sections without a DVI amplifier. Otherwise, with digital transmission and insufficient signal quality, the signal processing breaks down due to high bit error rates and the picture remains black.
DVI compatible extensions
DVI cables are available in different versions. So you can buy a DVI connector with different second connectors. So port A would be DVI and port B for example VGA or HDMI to easily connect your monitor and graphics card.
DVI and VGA
DVI cables are also capable of transmitting analog signals. Thus, it is possible to operate VGA-capable monitors via a suitable adapter on the DVI interface.
DVI and HDMI
The DVI interface has another advantage: it is compatible with HDMI and so it is possible to connect a computer or notebook with HDMI output to a monitor that has a DVI input. All you need is the appropriate cable with HDMI connector on one side and DVI connector on the other. You should know that DVI does not transmit audio signals. The sound must then be routed separately, for example via an extra RCA cable. Modern connections, such as HDMI, USB-C or DisplayPort, transmit both picture and sound.
What should be considered when buying?
DVI comes in three main formats. DVI-I, which transmits both analog and digital signals, DVI-D, which is made exclusively for digital video data, and DVI-A, which only processes analog signals. DVI-A is used exclusively on adapter cables for VGA. The DVI-D format is the most common connector and DVI-I is the most commonly used connector, as it is compatible with all other formats. DVI-D cables are used to create a digital connection between the output (usually the graphics card) and the flat panel monitor.