Please give up VGA & LVDS!

By Bob Raikes

I thought I’d pick up on another of the stories from this week’s issue, the release put out by the big PC and chip companies in support of a switch to DisplayPort and HDMI. Even now, with widespread and growing support, the companies are suggesting another five years before VGA and LVDS disappear. That will make VGA around thirty years old! I’m proud to say that this very long lived and clearly very functional interface was developed in the UK at IBM’s Hursley labs, around 70km from the Display Monitor office. Although originally designed just to meet the needs of the then new IBM PS/2 PC architecture and its innovative VGA graphics mode of 640 x 480 x 60Hz, it has proved amazingly adaptable over the years, and almost un-killable (my own word!).

There have been many attempts to kill VGA, and we’ve reported in the pages of Display Monitor on the VESA Ehanced Video Connector in 1996, Plug & Display in 1997, DFP in 1998 and then DVI, which finally, at least, made some impact. There were also attempts in Japan to define other digital display interfaces.

Although DVI was a significant step forward, the connector was very bulky, partly because it was also intended to handle analogue as well as digital signals. That made it relatively expensive, but, more importantly, it was clear that it was never going to be usable on the very slim and ultraportable machines that were starting to appear. Development of DVI effectively stopped and eventually, in 2005, the DisplayPort standard was developed for PCs. Meanwhile, HDMI had been developed for digital consumer and TV applications after the establishment of a working group in 2002 (and developments continued of VGA – does anyone else remember NAVI or VGA Express?).

HDMI has seen rapid adoption in consumer and entertainment devices and became the de facto consumer digital display interface quite quickly. It rapidly became the ‘digital SCART’, a simple single connector for audio and video. There was a strong view that the PC industry should simply adopt HDMI but, for a variety of reasons – some financial, some political and some technical – there was a belief that an alternative was needed to HDMI for professional and IT applications, so DisplayPort has, slowly, gained momentum. The support of AMD and Intel in chipsets has been a critical part of this.

As I mentioned in my comments on the news article, there is a clear and visible difference between the use of analogue and digital interfaces in the visual performance of displays. A monitor connected through its digital port is brighter and sharper than the same monitor connected through VGA, but I see very little real marketing of this message. It seems to me that one of the key issues in persuading buyers to accept systems without VGA is to persuade them that there is a real benefit. I don’t believe it is a difficult idea to sell, but it will be much easier to get buyers to change if they see the benefit rather than them seeing the shift as some kind of coercion or just as a cost-saving measure for manufacturers. We’d be happy to work with companies that want to persuade buyers, or the press, of this.