Ok – So last week I mentioned that HDMI was not the latest, it was just the latest craze. So the latest type of port and connector is now the DisplayPort.
So, Here I am at a show in Augusta Georgia a few weeks ago and I came across my first DisplayPort compatibility issue. Our client’s HP laptop had a DisplayPort output and the monitor had a HDMI input. Well you should have seen me running around town looking for the adapter having no clue what the port was even called. I showed them a photo or just told the sales people it looked like HDMI but one side was chopped off or 90 degrees. After my 5th store one savvy tech person finally said “oh – you are talking about a DisplayPort”.
Well then I learned that Mac users are well familiar with this term as they use a mini DisplayPort connection all the time. So once he knew what I was looking for he easily showed me a passive DisplayPort to HDMI adapter cable which took care of the connection problem. I did get lucky though as the DisplayPort graphics card in the laptop could recognize the monitor connection as HDMI and could output an HDMI signal. Note that I said that the cable was a passive adapter cable. It is very important to understand when a passive adapter will work and when an active adapter is needed. Hold on till next week and we will go over passive adapters and active adapters. Active adapters are also referred to as converters.
So in all this confusion you’re possibly asking why did we need another type of port and cable. Well, I asked the same question when the Phillips screwdriver tip was invented. Now look at how many different types of screwdriver tips there are. Oh well, I digress – so let’s get back to the DisplayPort. In my research the biggest reason that I have found for the premiere of the DisplayPort is that it is royalty free where HDMI charges 4 cents per device. That doesn’t seem like much but I guess if you are a manufacturer that could be a lot. But that is not the only reason. Ok – Here is some detail. About three years after HDMI was introduced came the DisplayPort. It was designed specifically to go from a graphics card to a monitor in the computer world where HDMI’s roots started in TV’s and DVD players. Basically HDMI came from the consumer electronics world. In other words the DisplayPort is a computer interface while the HDMI port is home electronics interface. The DisplayPort was designed to replace the DVI connection while HDMI was designed to replace the Composite, RGB and S-VHS connections once monitors went digital.
These two ports have different standards and capabilities with the DisplayPort reaching new heights in bandwidth and long distance cabling. The DisplayPort uses a packet based transmission system while HDMI and DVI use a system called TMDS meaning Transmission Minimized Differential Signaling. The DisplayPort packet system provides a more flexible use of bandwidth. It comes in one, two, and four link versions with increased data capacity with each version. The 1.2 or middle version is good enough for most applications as it easily surpasses HDMI at 17 Gigs per second (GB/s). HDMI maximum rate is around 10.4 Gigs per second (GB/s). Don’t worry – either way you only need about 750 Megabytes per second for 1080P video. The DisplayPort has many other features but I would get tongue tied trying to explain them so will just stop with this basic information.
As always, please respond with your questions or comments and let others know about EXHIBITOR LOUNGE.COM. We will see you next week. Until then, I am your host Michael Gray telling you to RELAX in the Exhibitor Lounge.