DVI (Digital Visual Interface) is a standard for transferring digital video between computers and high-resolution displays. It was introduced in 1994 and has since superseded analog signals carrying VGA-type cables.
DVI is based on a panel Link and utilizes a high-speed serial link called transition minimized differential signaling (TMDS). Single-link DVI has 19 pins; dual-link adds six pins at the center for a second transmitter increasing bandwidth and supporting resolutions up to 2560 x 1600.
1. Cable Length
The length of a Dvi cable can have a significant effect on the performance of the signal. As the cable length increases, attenuation degrades the signal.
This attenuation can lead to image degradation, pixel ‘sparkling’ and screen flickering. Even a short cable can cause issues.
DVI cables are designed to work within a specified distance, but the actual distance can vary widely depending on the devices and configurations. For this reason, it is recommended that a powered DVI signal booster be used on long runs for maximum signal quality and to reduce the risk of cross-talk.
VGA, on the other hand, has no built-in maximum length limit, but a longer cable does negatively affect the signal. Generally speaking, VGA cables can handle a distance of about 50 feet (about 15 meters).
2. Connectors
The connectors used in Dvi cables affect the performance of the cable. DVI cables use two types of connectors: single link and dual link.
Single Link DVI Cables are designed to support resolutions up to 1920 x 1080 at 60 Hz. They have 12 of 24 pins, whereas dual-link Dvi cables use all 24 pins and can support resolutions up to 2048 x 1536 at 60 Hz.
When sourcing products, it’s important to know which type of connector is required. For example, if you want to connect an HDTV or a video projector to a computer, you’ll need to get a Dvi cable with a male or female DVI-D receptacle.
Another common type of DVI cable is the DVI-A. This type of connector transfers analog signals only and is generally used to connect a DVI card to an older monitor, such as a CRT monitor. This type of connector uses four extra analog pins to help transmit the signal, but it still has a lower quality than DVI-D.
3. Shielding
Shielding is a critical element of any cable because it protects it from electrical interference. This can cause failures and affect the performance of your system.
The shielding used in Dvi cables can be made from a variety of materials. Some are metals like copper and silver, while others use plastics or water-extended polyester (WEP).
A shielded cable can improve its signal quality and performance by preventing EMI/RFI/ESI (electromagnetic interference, radio frequency interference, electrostatic interference) from affecting it. In addition, it can reduce insertion loss and skew.
Shielding also prevents electrical interference from being radiated back into the signal, which can reduce the risk of damage. It is a crucial component of any DVI cable.
4. Power Boosters
DIV Cable manufacturers are often challenged to make cables perform better over longer distances. Small gauge twisted pair TMDS lines can suffer from attenuation and other performance issues that can cause signals to be degraded, making them difficult to deliver in a usable condition.
One way to help long DVI cables carry their weight is with the aid of a power booster. These devices, which may use an external power supply to help mitigate signal degradation, are a must-have for anyone looking to extend the range of their DVI video system.
Gefen’s DL Booster Plus uses a plug-in power supply to enhance the performance of DVI signals and extend sparkling clear video images up to 200 feet at 2560×1600. The device is also notable for a number of other reasons, including its robustness to the DDC signal – a key component in delivering high-resolution digital signals from the source to display. The company also has a line of other powered DVI accessories that will help you get the most out of your system.