Monitor ports

Know the difference between video ports on your monitor and computer before you purchase

So you bought a brand spanking new computer delivered to the office, unpacked ready to go. But, the cables on your treasured twin 27″ monitor setup don’t match any of the available ports on the computer! What’s going on, aren’t they all the same? No, they’re not and this is to do with legacy standards and technology changes over the past thirty years.

Choosing the right monitor ports is crucial before purchasing a computer or monitor due to compatibility and connectivity requirements. Different tasks and devices demand specific ports such as HDMI, DisplayPort, USB-C, or VGA, each offering distinct advantages in terms of resolution support, refresh rates, and multi-monitor setups. Assessing these ports before you purchase a new computer or monitor ensures seamless connectivity without disappointment.


A standard monitor port known as VGA was first introduced by IBM in 1987, see the image below. Though monitor resolution was acceptable at the time, its shortcomings were quickly realised as advanced graphics in gaming and image software (e.g. Photoshop) appeared. DVI first appearing 1999 was designed to address the requirements. Later HDMI and DisplayPort emerged with better transfer speeds allowing for high-definition resolutions on monitors (HDR).
Monitor manufacturers, in turn, had to produce screens capable of displaying high-definition graphics to match the emerging standards. Adding to their woes, these new designs are patented, requiring licensing for both monitor and computer manufacturers to produce them. The result today is a mix of different port types on both computers and monitors. Monitors can last a long time, so it’s not unusual for hapless purchasers to discover that their monitor doesn’t have the right port to match their new computer

  • USB-C
    The latest technology aims to standardize all port types, not just for monitors but also for power supplies and common peripherals like docks and portable hard drives. Note that Thunderbolt cables are now the same as USB-C, and ports are backward compatible. However, USB-C technology has caveats and can be tricky to understand. These are discussed in more detail later.
  • DisplayPort
    DisplayPort was introduced in 2006 as a competitor to HDMI released four years earlier. There are nuances, but overall DisplayPort is considered to superior to HDMI.
  • HDMI
    Introduced in 2002, HDMI quickly became the de-facto standard on computers and monitors. Most laptops have a HDMI port for connecting an external monitor.
  • Thunderbolt 1 and 2
    Was introduced by Apple in 2011 for connections between their proprietary devices. The connector shown above is the original design for Thunderbolt 1 and 2 now superseded by Thunderbolt 3 and 4, see next.
  • Thunderbolt 3 and 4
    The latest version are Thunderbolt 3 and 4 using the same port design as USB-C on the far left and backward compatible with USB-C devices.
  • VGA
    VGA (Video Graphics Array) was introduced in 1987 by IBM quickly becoming the de-facto standard for manufacturers. Though monitor resolution was acceptable at the time, higher definition technologies were introduced Still even today, some monitors come with this port as an alternative to HDMI or DisplayPort
  • DVI
    DVI (Digital Visual Interface) first appearing 1999 was designed to address the shortcomings of VGA above. This port is still found on many older monitors and desktop computer systems. It’s rarely standard on new models and is rapidly disappearing.

Most monitors and computers offer more than one type of port

  • Monitors offer at least two types of ports typically HDMI and another. You can only use one on a given monitor
  • Most desktop computers offer at least two port types typically HDMI with a DisplayPort or VGA. This allows you to set up two or more monitors
  • Laptops generally come with one port which is typically HDMI. To set up multiple monitors for a laptop requires a docking station.

Wait there’s more?

Yes, there are other micro versions of the same technologies introduced for laptops. You rarely see these today but we include them below just in case you’re confronted by that unidentifiable port on your laptop! Note that though Mini-DVI looks very similar to standard Thunderbolt 1 and 2 ports above, they are not the same thing.

Adapter cables and converters

There are adapters available to convert for example HDMI to DisplayPort, which can save the day if you’ve fallen into the port trap discussed here. However, for technical reasons, be aware that they don’t always work, especially if converting using a dock. This can be due to the cable itself, the computer, or the dock. For the layperson, it really is a trial-and-error situation, which is not ideal at all. For the best results, aim to match the ports on your monitor and computer as best you can.

Beware of USB-C

USB-C technology, while versatile and widely adopted, comes with several caveats. Not all USB-C cables are equal; some may only support charging while others can handle data transfer or video output. The problem is the cables and ports are identical to look at. Charging speeds can also vary, as not all USB-C ports or cables deliver the same power. Data transfer speeds differ among USB-C devices, with some supporting older USB 2.0 standards and others offering faster USB 3.2 or higher speeds. Compatibility issues can arise due to differences in supported standards, leading to reduced functionality in some devices. Additionally, the durability of USB-C connectors can vary, with poor-quality cables or ports wearing out faster and causing connection problems.

A consideration is video output limits. While USB-C can carry video signals like HDMI or DisplayPort, not all USB-C ports support this feature, which can be confusing when connecting to monitors or TVs. This is important if you’re looking to connect a dock to a laptop for this purpose. Port availability is also a concern, as many new devices are moving to USB-C exclusively, necessitating the use of adapters for older peripherals. This shift can lead to potential inconvenience and additional costs. Understanding these points can help users make better decisions when purchasing USB-C devices and accessories.
When it comes to USB-C, for clients of Article 5, it’s best to reach out to us for advice before purchasing or upgrading.

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