Subscriber Discussion

Displayport For Surveillance Monitors?

Has anyone used DisplayPort technology for video surveillance monitors or computer workstations (as opposed to HDMI)?

It appears to be an interesting concept for linking together multiple high-definition monitors from a single port, which would seem a great fit for surveillance monitoring workstations, but I don't see many manufacturers supporting it yet, especially with monitors or displays.

For those not familiar with Displayport, it is a VESA display adaptor designed to replace DVI that is royalty free, as opposed to HDMI, which is licensed.

DisplayPort is commonly used for outputs on laptops (Apple has been using it exclusively for years) and multi-head video cards like the Matrox M series, but rarely do I see it used on monitor inputs. Most commonly, you just buy an adapter cable and convert it to whatever format you need at the far end (HDMI, DVI being most common). DisplayPort could have taken off had it come a little earlier. The prevalence of HDMI in consumer gear killed it though.

Oh and one other thing: DisplayPort is royalty-free, while HDMI must be licensed. Which you would think would encourage more devices to adopt it, but it hasn't gone all that far.

Like Ethan notes, my laptop has display port. Also, like Ethan notes, I have an HDMI adapter plugged into it and it irritated me that I had to buy one.

This was also notably an issue when HDMI first ended up on laptops, because most displays at the time were DVI, so you needed to adapt it. I kind of feel like I need to buy a cable anyway, and I can order a cheap one from Amazon for $8 and I've had no problems.

John, my exposure has been with Bosch. The new DivarIP 7000 has a display port for use as local monitor 2. Additionally some of the HP workstations that we have encountered use a display port as well. We plan ahead and spec the correct display port cable when we do our BOM's.

We've connected some monitors to add-in cards that had display ports, but had to use adapters to convert to HDMI to connect to the monitor.

Monitor manufacturer's don't seem to picking up too much on the connection.

It seems a shame that this is not catching on as it is royalty free and the ability to daisy-chain multiple HD monitors together would seem to a perfect fit for the surveillance market. Form my experience with HDMI, a spearate cable is needed for each individual monitor.

We use it all the time along with a DisplayPort to HDMI connector but the only reason we do is the new corporate standard PC (from HP) has display port instead of DVI or HDMI.

Ross - I'm assuming that's primarily because there aren't many monitors or displays supporting the DisplayPort input yet, correct?

Correct. Out of the six "standard" displays our IT department supplies, none have the input.

How does this work with DisplayPort?

This HDMI vs DisplayPort article says:

"A single DisplayPort interface can support up to four monitors at 1920-by-1200-pixel resolution each, or two monitors at 2560-by-1600-pixel resolution, with each display receiving independent audio and video streams. And since some GPUs can support multiple DisplayPort interfaces, you can daisy-chain compatible monitors to connect as many as six displays to one source."

It's daisy chained? also references:

"While the daisy-chainable monitors are one way to achieve multiple displays, we next tell you about DisplayPort 1.2 multi-stream “hub” devices that will allow you to use the legacy monitors you may already own. These hub devices will also become available next year, and you will hear about them in our next post."

Are these hub devices available? Here's one review of a model from earlier this year.

In theory, you can daisy chain monitors with DisplayPort. It's high enough bandwidth you can do this via one cable. In practice, though, you don't see many monitors with a DisplayPort out, only in. Apple does it with their Thunderbolt display, but that's not straight DisplayPort. It's DisplayPort encapsulated with Ethernet and more on a single Thunderbolt connection.

The hubs are news to me. That's potentially game changing, because it puts a lot more monitors in a smaller package. This is quote from that review that really struck me:

Take a profession card like the W600, for instance, it has 6 DisplayPort 1.2 plugs which enable it to drive 24 separate monitors from a single-slot card.

That's a video wall in a single slot video card. Of course there will be processor limitations to displaying that much video on a single client, but spending a bunch of money to add multiple processors and make a client a really beefy machine is still going to be far cheaper than getting a true video wall setup. It's interesting, at least.