Are DisplayPort Cables Bidirectional?

It’s hard enough to master all the different cables we interact with on our day-to-day engagements. 

And yet, we’re expected to understand the interactions between the cables themselves and the devices they connect.

Not just because failing to do so could jeopardize our efforts to transmit data from one device to another. But also because learning how cables and devices relate with each other can save us precious time and frustration trying to figure out how to set your connection right.

When handling DisplayPort ports and cables, one of the foremost things you want to know is whether DisplayPort cables are bidirectional. And today, you’re going to learn whether they are indeed bidirectional. 

With this knowledge, you’ll never be at a loss when it comes to connecting DisplayPort cables, even when faced with a device you’ve never handled before.

Are DisplayPort Cables Bidirectional? 

Yes, DisplayPort cables are bidirectional, they transport data in any direction. So it doesn’t matter which cable end goes into your output device and which one goes into your input device. When you switch up the cable ends, the cable will still send data across the connected devices.

That means that you can plug either end of the cable into your source or display device, and the cable will successfully transmit video.

This is the direct opposite of how unidirectional (or directional) cable formats operate. 

With directional cables, data flows in one direction only. So you cannot switch up a directional cable such that you connect the end that goes into the source to the display device. If you do that, there will be no signal transfer.

Your DisplayPort user manual will clearly state the bidirectional design of the DisplayPort cable. 

In addition, the manufacturer may include an illustration of a double-headed arrow on the cable and on the cable packaging — it looks like two arrows facing away from each other. These arrows indicate that the cable transmits data in either direction.

This is how the bidirectional cable symbol looks like:

DisplayPort ↔ DisplayPort

Directional cables are symbolized by a single arrow that shows the direction of data flow. This is how the directional cable symbol looks like:

HDMI → HDMI

So if you ever get confused about the direction of signal flow in a DisplayPort cable, remember the double-headed arrow or look for the symbol on the package.

You may ask:

What if the two ports you’re connecting are of different DisplayPort specifications? 

It doesn’t matter that the output DP port has a different specification than the input DP port. 

Because DisplayPort has backward compatibility with older DP versions, data exchange will occur even when the connected devices support different DisplayPort versions. And the variance in the specification does not affect the bidirectionality of DisplayPort cables.

Is DisplayPort 1.2 Bidirectional?

Yes, DisplayPort 1.2 is bidirectional. You can use either end of the DP 1.2 cable in the source device or monitor to send data in either direction. 

Assuming you want to transmit a signal from the DisplayPort 1.2 port on your laptop to the DisplayPort on your TV. 

You can plug any end of the DisplayPort cable into the laptop, then connect the other end to the TV. 

Now unplug the cable and reverse the connection so that the end that you previously plugged into the laptop goes into the TV, and the side that plugged into the TV now plugs into the laptop. You’ll notice that data transmission occurs uninterrupted.

So it doesn’t matter which cable end goes into the source (output) port and which one goes into the display (input) port.

It also doesn’t matter if one device features the older DisplayPort 1.2 version and the other supports a newer DisplayPort version. DisplayPort’s data transmission remains bidirectional, even when dealing with variant DisplayPort specifications.

Does It Matter Which Way the DisplayPort Cable Goes?   

No, it does not matter which way the DisplayPort cable  goes. That’s because DisplayPort cables are bidirectional. Therefore, they can send data in either direction. 

With bidirectional cables, you are not limited to connecting each specific end to a particular port. Instead, you can interchange the ends, and this action won’t interfere with the cable’s ability to transmit signals.

For example:

On Day 1, you can insert one end of the DisplayPort cable — let’s call it “End A” — into your source device, and insert the other end — call it “End B” — into your monitor. 

On Day 2, you can insert End A into the monitor and then insert End B into your source device, effectively reversing the order you followed on Day 1. 

In both cases, the data will flow as expected, and you’ll receive the signal on your monitor as expected. Switching the ends and plugging them into different ports does not affect the cable’s efficiency. 

This compatibility isn’t limited to a single DisplayPort specification, but applies to all DisplayPort versions. And it works even when you’ve connected devices that have varying DisplayPort versions.

So, say your laptop has a DisplayPort 1.4 port, and you connect it to the DisplayPort 2.0 port on your monitor. 

Whichever DP cable you use to connect the two will successfully transport the signal, regardless of the cable end you plug into the source or display device.

That’s contrary to how unidirectional cables work where, once you switch up the DP cable ends, data cannot move from one connected device to the second connected device.

Conclusion

DisplayPort cables can transmit data in any direction, so they are bidirectional. That means you don’t have to connect each cable end to a specific port, either output or input. 

Instead, any cable end can plug into any DisplayPort output or input port.

This bidirectionality applies even when the cables link devices with different DisplayPort versions. 

Therefore, you can connect the cable in any direction when one of the devices supports a more recent DisplayPort version than the other device. 

Just like you would connect the cable in any direction when linking devices with similar DisplayPort specifications.

The bottom line?

It doesn’t matter the direction the DisplayPort cable goes. Either way, it will effectively transmit the DP signal.