You might have heard terms like DVI single-link and dual-link being tossed around in the context of display cables. Although they’re often contrasted, the two links are actually more similar than you might expect.
Let’s start from the beginning. DVI stands for digital visual interface, and it’s a kind of display cable. It was designed to be a better alternative to the older style of video graphics array (VGA) connectors.
DVI cables come in three main varieties depending on the type of signal that they can carry. DVI-A carries only analog, DVI-D carries only digital, and DVI-I is an ‘integrated’ cable that can transmit both. DVI-I and DVI-D cables are the most common, with DVI-A being quite rare.
Since you can’t find many DVI-A cables around these days, and they’re a generally older model, they don’t come with a dual-link option at all. They default to a single-link format. So, if someone is talking about dual-link DVI, then you know it’s either DVI-I or DVI-D.
Now we’ve reached the meat of the issue: what is the actual difference between single-link and dual-link DVI cables? Well, all DVI cables use TMDS transmitters to move information. The number of TMDS links is what defines a single-link and a dual-link cable.
As the names imply, a single-link DVI has only one link. A dual-link cable has two, which in simple terms, allows it to transmit almost twice the amount of information. That means dual-link cables are superior in that they support higher resolutions and better bandwidth.
Even so, you don’t need to rush out and buy a dual-link DVI cable. There’s a lot more to the comparison, which we’ll dive into next. Let’s get started!
Single-Link vs. Dual-Link DVI: A Side-by-Side Comparison
|Single-Link DVI||Dual-Link DVI|
|# of TMDS Links/Transmitters||1||2|
|Resolution Supported||1920 x 1080p at 60Hz||2560 x 1600p at 60Hz|
|Bandwidth Supported||4.59 GBps||9.99 GBps|
|Number of Pins||18||24|
|Number of Pin Clusters||2||1|
|Available with||DVI-A, DVI-D, and DVI-I||DVI-D and DVI-I|
Single-Link vs. Dual-Link DVI: How Are They Different?
There are three main categories where single-link and dual-link DVI vary. We’ll cover each of these categories and their practical applications.
Pins and Visual Differences
When trying to identify a single-link or dual-link DVI, you just need to look at the pins. In the case of a DVI slot, you can use the pin slots to identify it the same way.
A single-link DVI has 18 pins in total. The way to identify a dual-link–-and spot the root of their differences–-is to look for 6 more pins in the center of the plug. These pins help DVI cables do their job well. More pins mean more data carried through the cable at once.
An even easier way to tell them apart is to avoid the tedium of counting pins altogether. Single-link DVI has two clusters of 9 pins, which gives it a unique look. The two clusters are quite distinct from each other.
On the other hand, dual-link DVI plugs have no gap. The 6 extra pins are added right in between the original two clusters, creating a long rectangle of pins.
Essentially, if there’s only one cluster of pins, then you’re looking at a dual-link DVI. If you’re seeing two clusters, then it’s a single-link DVI. Both of these plug types are wildly different from the much smaller and newer DisplayPort or HDMI technologies.
The main issues with DVI cable compatibility include the type of transmission (analog vs. digital) and the number of pins (single- vs. dual-link). Remember, DVI-A is an analog cable, DVI-D is digital, and DVI-I can transmit both analog and digital.
Every single-link DVI cable can be connected to any dual-link or single-link DVI-I port. That’s because every pin will still have a corresponding pin slot to go into. There’s also no incompatibility because DVI-I is a hybrid port. Whether analog, digital, or both, DVI-I can support any type of DVI transmission.
So, using that logic, you could put a single link DVI-D in a dual-link DVI-I port and it would work just fine. You could also use a single-link DVI-D cable in a dual-link DVI-D port if you so choose. In the latter case, both the plug and the port use digital transmissions and there is no conflict.
Flipping the situation around, you wouldn’t be able to use a dual-link DVI-I cable in a single-link DVI-D port. For one thing, there’s nowhere for the extra pins to go if you try to connect any type of dual-link cable into a single-link port. It’s already incompatible based on that alone.
You’ll also be stuck because a DVI-D port can only use digital. That setup is fundamentally incompatible with DVI-I, which uses both digital and analog transmissions. Generally speaking, you can’t use a DVI cable in a port that doesn’t support the given format.
For another example, DVI-A does analog only. Thus, you would need a DVI-A or a DVI-I slot to use. As long as you’re accounting for the pins on a single-link or dual-link cable, you can use this logic to decide compatibility.
Bandwidth speed is the underlying benefit of dual-link DVI. Since a dual-link has more pins than a single-link, it can transmit more information. In this case, that translates to a better bandwidth for your display devices.
The increase isn’t small, either. A single-link DVI, regardless of whether it’s a DVI-I or a DVI-D, will support a maximum bandwidth of 4.59 Gbps. Dual-link has twice the bandwidth of a single-link at 9.9 GBps.
Notably, DVI technology was released back in 1999. Although it’s newer than the analog-only VGA, it’s definitely an old cable tech at this point. Even dual-link DVI-I is bested by contemporary types of graphics displays like HDMI.
As a point of reference, HDMI cables can range in bandwidth between 10.2 Gbps and 18 Gbps. Even the low point of an HDMI cable will trump the high point of a dual-link DVI when it comes to bandwidth.
Dual-link DVI has a much higher max resolution than single-link DVI. This, just like bandwidth, comes from the fact that dual-link DVI has more pins/TMDS links to transfer information through.
Using 60Hz as a benchmark, dual-link DVI can support a maximum resolution of 2560 x 1600p. This might not sound impressive compared to some of the modern high resolutions that we’re starting to get used to. Compared to single-link DVI’s 1920 x 1080p resolution, though, it’s a massive leap.
To appreciate DVI’s advancements, you have to look at the other technology of the time. VGA cables could only support a max resolution of 650 x 480p. Put into perspective, dual-link DVI is actually a very respectable resolution even by today’s standards.
Single-Link vs. Dual-Link DVI: 5 Must-Know Facts
- Dual-link DVI supports a better resolution (2560 x 1600p) than single-link DVI (1920 x 1080p).
- All forms of DVI, including dual-link, can only transmit visual data and not auditory.
- The maximum bandwidth of a dual-link DVI-I cable is around 9.9 Gbps.
- Dual-link DVI is an improvement upon single-link DVI and has more pins.
- Single-link DVI cables can usually be plugged into dual-link ports, depending on the type of signals transmitted.
Single-Link vs. Dual-Link DVI: Which is Better?
After all that, you might find that there’s really no point in worrying about whether you have a single-link or dual-link DVI. If you’re purchasing new products, it’s generally better to opt for a better technology than DVI.
In the case that you’re already stuck with DVI ports and plugs, then it’s simply a matter of using whichever DVI cable is supported. Not all devices make use of dual-link DVI, and in fact, most of them only support single-link DVI.
It’s not that you’ll be barred from using dual-link–-it’s just that you won’t be reaping the benefits because the actual devices don’t support dual-link.
You should base your purchasing and usage decisions on the quality of the cables and devices in question. Although dual-link DVI will give you better bandwidth and graphics, it isn’t the cable alone that matters. The device’s capabilities matter far more.
Ultimately, you should just choose the type of cable (DVI or otherwise) that works best with the device you have. That’s all there is to it, once you filter through the hype of dual-link or single-link DVI.