DisplayPort

There are a lot of standards for getting video information from a computer to a monitor or television. Some of them also include audio along with the video feed.

VGA has been around since 1987, and it is certainly a bit dated. It uses analog signals to send information to monitors, which has a major flaw: if the signal is passed over a weak cable or a long distance, the picture will look distorted. This is much like the difference between the quality of music from a radio station and the quality of music streamed over the Internet.
One advantage to some of the older analog transfer mechanisms is that on old CRT monitors, the monitor itself does not have to do any processing to make the image appear on the screen. That means the computer, game console, or other monitor input can know exactly what is being rendered on the screen at any particular time. This, for example, was used for the Nintendo Entertainment System’s Zapper and R.O.B., which used precise timing with a CRT monitor to send signals between the game and the controller. These games would not work on digital displays.

But digital specifications for transmitting video signals are more reliable and less dependent on having a good cable. As long as the cable can carry simple voltage differentials, ones versus zeroes, over long distances, it can be used to transmit digital data.

DVI is a digital specification, but DVI-I ports can also take in VGA adapters; these ports, in fact, transmit both digital and analog signal data. HDMI is another digital specification, and it can also be used to transmit audio.

But DisplayPort is particularly interesting. It is a spy tools for cell phones proprietary specification, though monitor and graphics card manufacturers do not have to pay royalties to implement it. DisplayPort is designed to replace DVI and VGA. Inexpensive adapters are available to convert between DisplayPort and other digital formats like DVI and HDMI. Active adapters can also make a conversation between DisplayPort and VGA.

DisplayPort has a few distinct advantages over older specifications. One is pure bandwidth. A single DisplayPort is able to drive four 2560×1600 displays at 60 frames per second simultaneously (because DisplayPort allows using a hub or daisy-chaining to connect multiple displays over one connection). DisplayPort can also be used to drive displays at much higher refresh rates, like 144Hz, that VGA can’t handle and that DVI can only handle with DVI-D, which is dual-link DVI. Only newer versions of the HDMI spec are able to handle refresh rates this high.

DisplayPort 1.2 supports AMD’s FreeSync standard. This is a free, open-source standard that AMD developed to allow monitors to change their refresh rate dynamically with the input. This can remove stuttering or inconsistent frame duplication when the monitor’s refresh rate and the content displayed onscreen aren’t factors of each other. Adaptive refresh rates can also improve energy efficiency, because static screens do not need to be refreshed nearly as often as dynamically-moving screens. This is in rival to NVIDIA’s G-SYNC technology, which requires a separate module built into the monitor. Since FreeSync and DisplayPort are free to implement, these might be better options for manufacturers and consumers.

Lots of graphics cards these days come with multiple DisplayPorts, and fewer and fewer are coming with VGA ports on them. The shift to digital is nearing completion, and it looks like DisplayPort is coming out on top regarding which one will be dominant in computers and monitors worldwide. Don’t be left out, tinkering with adapters, non-standard configurations, and potential degradation of quality. When you’re buying new components, take some time to evaluate if you care about their implementation of the DisplayPort specification.