New Tech Is Not Always Good

by Bob Seidel

Oh my aching parts bag. Just when I thought it was safe to come out of the woods, here comes another PC display connection type - the DisplayPort. But new is not always better and perhaps you should be wary of this one. The rationale is, of course, buried in history.

I hate doing another high-tech column as many of my readers can't get through them. But this is an issue that you will face when you buy your next PC and so you need to be aware of it.

Back in 1982 when the IBM PC first became available, it supported two types of displays (monitors): the monochrome (i.e. one color - in this case green) display had a screen with fairly good resolution, but it didn't support any form of graphics. The color display did support graphics, and eventually as technology marched on it completely displaced the monochrome display. The color display used the familiar and standard VGA connector, and it has been that way since. The VGA connector is what we call a D-shell connector (it looks faintly like a capital letter D) and has 15 pins in three rows and is usually colored blue. As technology goes, VGA had a very long life. But the downfall of VGA was that it was an analog interface and therefore not precise.

Flat panel LCD displays became popular and were capable of using digital signals. This resulted in the birth of the DVI interface. DVI was fully digital and used a rectangular, ivory colored connector. The DVI cable also carried the analog signals, and so you could get a simple dumb adapter (i.e. no electronics in it) to convert and be able to attach an older analog VGA display to a DVI connector. Many displays come with the capability for both inputs.

Many low end PCs today still come with just VGA, but the higher end PCs all support DVI. DVI and VGA were open standards and thus did not cost the manufacturers anything to use.

But the world wasn't stable yet. The problem was that the DVI connector did not support digital audio - just video. This made DVI impractical for use on TVs for a "single cable" solution. The response of the TV industry was to support another standard, HDMI.

HDMI has become the standard for high-definition televisions today, but can also be used for other components in your home theater as it also carries audio and even control signals. You can use an HDMI cable to connect your receiver (stereo) to your cable box, just as you can use one connect it to the TV. Or you can use your TV's built-in sound system, and just have one cable from the cable box to your TV. One cable for all - sounds like nirvana, right?

Well, perhaps not. The issue is that HDMI is not an open standard, and the manufacturers must pay a license fee and a per-unit fee to the consortium that developed it. This prompted a parallel effort for an open standard, which has become something called DisplayPort.

Apparently HDMI and Display Port both were being worked on in parallel, but HDMI was first to market because it was developed by a limited-sized industry group with a profit motive. DisplayPort is being developed by VESA (the industry standards group) as an open technology and thus was slower to be approved due to the usual bickering amongst the members.

Dell is the only current manufacturer championing DisplayPort, and it has started to include it on many of its high end PCs.

So the next time you buy a PC from Dell (or perhaps others) you will be faced with a dilemma: Many industry pundits are recommending that the industry stay with HDMI as it is already the de-facto standard and that the fees charged are small for the volume of devices being sold. Of course if you go with DisplayPort, you will also need a DisplayPort equipped display or TV, and those are few and far between right now. And worse, if the PC industry eventually supports DisplayPort and the TV industry stays with HDMI, we lose compatibility and you won't be able to plug a TV directly into a PC.

Isn't life in the alphabet soup technology world fun? To sum it all up for now, the industry pundits seem to recommend avoiding DisplayPort for your PC display, and it hasn't made any dent at all yet in the HDMI armor for TVs. Time will, of course, tell.

(Bob Seidel is a local computer consultant in the Southport - Oak Island area. You can visit his Website at www.bobseidel.com or e-mail questions or column ideas to him at bsc@bobseidel.com. For specific inquiries, please call Bob Seidel Consulting, LLC at 278-1007.)