We thought it would be useful to describe the different connectors for computer screens:


VGA


This is a blue (15-pin) D-shaped port and transmits an analogue video signal only with no sound. This is really the least high-quality connector so should be used as a last result.


It is possible to convert simply between VGA and DVI if required.




DVI

The larger white (24-pin) D-shaped port is called DVI and whilst it also only transmits video signal with no sound, it is a digital signal which results in a higher quality screen image.


This standard is a little more complex as there are multiple implementations, including DVI-A/DVI-D/DVI-I and dual display - as it has been superceded by both HDMI and DisplayPort, it's best to use one of the newer interfaces if possible.

If required, it is simple to convert between DVI and both VGA and HDMI.


HDMI


HDMI is a 19-pin connector which is rectangular with two of the corners cut/chamferred and transmits both video and sound over the same cable.

Whilst the connector above is the most commonly found for HDMI, there are a number of alternates...most commonly mini-HDMI


The HDMI standard is also complicated by multiple specifications, ranging from the original v1 release to the most current v2.1.


  • v1 cables are limited to full HD (1920x1080)
  • v1.4 is probably the most common currently and was upgraded to allow UHD/4k (3840x2160) at 30k refresh rate
  • v2 cables add 60k refresh rates for UHD
  • v2.1 cables add 8k screen resolutions


DisplayPort

This is a newer 20-pin connector that is rectangular but with 1 corner cut/chamferred and as with HDMI it transmits both video and sound over the same cable, but it uses an entirely different transmission standard than HDMI  which makes it more reliable/accurate and more extensible since the protocol/standard can be enhanced without any need for changes to the hardware interface. 

Unlike HDMI cables, DisplayPort cables also "lock" the connector in to the plug, and DisplayPort also benefits from lower license costs so the cables are typically better value.


Displayport is also available in on alternate connector format called mini-DsiplayPort:


As is only to be expected from a standard that can eb extended, there are various DisplayPort specifications:


  • Up to v1.1 cables are limited to full HD (1920x1080)
  • v1.2 cables support up to UHD (3840x2160)
  • v1.3 and above support UHD at 120k refresh rate
  • v2 was only released in June 2019 and adds 8k display standards plus multi-monitor support