Most monitors will have a range of different inputs available, and your PC or laptop will also use different outputs, so it can be difficult to decide which is the best one for you to use. Under most general circumstances, you might be able to get away with using whichever cable you have lying around, but if you have more specific needs, such as carrying audio or using high resolutions or refresh rates, you’ll need to be more discerning in your choice of cable. We outline the different cables below and give you a few different usage scenarios to help you decide.
HDMI
HDMI, or ‘High-Definition Multimedia Interface’ to use its full name, is one of the most common connections. You’ve probably come across it on your television, set-top boxes, tablets, laptops and games consoles.
HDMI is unique among the many connection options in that it’s able to carry both uncompressed video and uncompressed audio. This is why it’s become the connection of choice for most multimedia devices as it’s a one cable solution (like SCART but so much less annoying). Other benefits of HDMI include functions such as HDMI-CEC (HDMI Consumer Electronics Control), which allows you to control numerous devices with one remote. For example, connect a soundbar to your television through a HDMI-CEC compatible port and the soundbar can turn on and off with your television and be controlled by a single remote.
HDMI has seen numerous revisions since its inception in 2002. Its most common version, used in most consumer devices at present, is 1.4 but there’s a newer, more exciting 2.0 specification now becoming more prominent. The main difference between the 1.4 and 2.0 specifications focus around bandwidth available. HDMI 1.4 has a bandwidth maximum of 10.2 Gbps/s whereas the HDMI 2.0 tops out at 18 Gbps/s.
The reason that bandwidth becomes important is due to the advent of 4K content. Due to the limited bandwidth of HDMI 1.4, only 24fps was possible at 4K resolution (3,840 x 2,160). Now, thanks to the extra bandwidth available in the 2.0 specification, up to 60fps at 4K resolution is possible.
Colour depth is also another area where the new HDMI 2.0 specification gains some advantages. Where 1.4 was limited to 8-bit colour, HDMI 2.0 has 10-bit or 12-bit available. This is important for when High Dynamic Range (HDR) content becomes available.
HDR can be described as the ratio between the lightest and darkest parts of an image. Typically, with standard dynamic range, you’re losing detail at either end of the light spectrum. Expose a scene for the shadow detail and you end up with blown out highlights, or expose for the highlights and you lose shadow detail. HDR allows a greater range of detail across the full light spectrum.
You’ve probably already come across HDR through photography. Most smartphones now have an HDR mode where they essentially take numerous images at different exposures and combine them. As HDR has become part of the Ultra HD standard, you can expect more Ultra HD Blu-ray content to take advantage. The likes of Amazon and Netflix are going to be streaming HDR content as well.
More often than not, if you’re connecting something to a television, HDMI will be your best, and likely only, bet. Most PC monitors will also include an HDMI input. The good news, where it comes to 1.4 vs 2.0, is that you don’t need to rush out and buy new cables. To take advantage of the 2.0 specification you just need both devices on each end of the cable to be 2.0 compatible. Any HDMI cable will do, and we’ve already seen that there’s no difference in HDMI cable quality.
The one thing to look out for are the different HDMI connection sizes. Not only is there full-size HDMI (Type A), but you can come across Mini HDMI (Type B) and Micro HDMI (Type C), too. These are commonly found on portable devices such as tablets, camcorders and action cameras, where their physically smaller connections are required. You can either buy HDMI-Mini HDMI/HDMI-Micro HDMI cables or you can buy Mini/Micro HDMI adaptors so you can use your full-size HDMI cables.
What's the difference between WQHD, QHD, 2K, 4K and UHD?
DisplayPort
Until HDMI 2.0 became a standard, DisplayPort had it beat when it came to high-resolutions. DisplayPort 1.2 has long been able to carry 3,840x2,160 resolution video at 60fps (or a refresh rate of 60Hz) and is the most common DisplayPort specification on most consumer monitors and devices now. This has 17.28 Gbit/s of bandwidth. A newer 1.3 specification is becoming more widely available, however, and this opens the floodgates to higher resolutions such as 7,680x4,320 (8K).
The main advantage of DisplayPort is the ability to output to multiple displays through Multi-Stream Transport (MST). You can do this by daisy-chaining compatible monitors over DisplayPort or by connecting a DisplayPort MST splitter to your single DisplayPort output on your PC or laptop. You have to work within the bandwidth limitations of whichever DisplayPort specification you’re using, such as two 1,920x1,080 monitors over 1.2 or two 3,840x2,160 displays over the DisplayPort 1.3 specification. As such, DisplayPort is often a great choice for those looking to use multiple monitors.
DisplayPort also has advantages where it comes to screen refresh rates through Adaptive Sync. This is what AMD has used for its Freesync implementation. Essentially this helps reduce screen tearing, which will be of particular interest to gamers. Like HDMI, some laptops and devices use Mini DisplayPort, so make sure you get the right cable.
DVI
DVI stands for ‘Digital Visual Interface’, and is another common connection found on PC monitors. Things can become a little confusing when you consider there are three different types of DVI. There’s DVI-A (analog signal), DVI-D (digital signal) and DVI-I (integrated analog and digital signal). Not only that, but DVI-D and DVI-I have single-link and dual-link versions. Nowadays, DVI-A is very uncommon, as it’s no better than VGA.
The differences between single-link and dual-link refer to how much bandwidth the cable can carry. A single-link DVI-D or DVI-I cable can carry 3.96 Gbit/s, which tops out at 1,920x1,200 resolution. Dual-link, on the other hand, physically has extra pins on the connectors, allowing a maximum bandwidth of 7.92 Gbit/s and 2,560x1,600 resolution. Although DVI is still a common connection, it’s becoming dated, so if you want to output a very high resolution you’ll need to use HDMI or DisplayPort instead.
VGA
VGA is the oldest of the four connections outlined in this article. It’s been around for decades, dating back to the days of thick, heavy CRT monitors of yesteryear. VGA stands for Video Graphics Array but can also be referred to as an ‘RGB connection’ or ‘D-sub’. While VGA can technically output to 1,920x1,080, the problem is that it’s an analog connection, so as you push the resolution higher you get image degradation as the signal is converted from analog to digital. Unless you absolutely have to, use one of the above connections instead of VGA.
Using a combination of HDMI, DisplayPort, DVI and VGA
Most motherboards and dedicated graphics cards will have multiple outputs. You can use a combination of these to output to multiple monitors. So if you have HDMI and DVI outputs, connect one monitor using HDMI and the other using DVI. As mentioned above, if you’re using DisplayPort and your graphics card or device supports Multi-Stream Transport, you can daisy-chain DisplayPort monitors, too.
