KNOW THE LINGO — WHAT IS DISPLAYPORT?

By: Joseph D. Cornwall, CTS-D
Technology Evangelist — C2G

Technical lingo is a kind of shorthand that's used to express concepts common to that specific topic or area of study. Technical lingo is important because it provides a very precise or unique "shorthand" description of a device, effect or concept. Unfortunately, if you aren't comfortable and familiar with the lingo of a topic it can be a tall hurdle to communicate efficiently with folks who consider the jargon of their field to be "self-explanatory." In this series of articles we'll lift the veils of misunderstanding from the lingo of the A/V industry.

WHAT IS DISPLAYPORT?

In May of 2006 the Video Electronics Standards Association (VESA) approved a new technology for transporting audio/video (A/V) data streams and a bi-directional auxiliary channel between a computer and a monitor, or between a computer and a home theater system. It made its debut as a license-free, royalty-free alternative to the rapidly growing HDMI connection, and as a replacement for the aging Low Voltage Differential Signaling (LVDS) technology that had been the interface of choice in the computer world since its introduction in 1994. VESA envisioned DisplayPort becoming a replacement for VGA, DVI, and FPD-Link, with backward compatibility to VGA and DVI by using active adapter dongles. In its original incarnation, DisplayPort was essentially incompatible with HDMI and other TMDS and HDCP-encrypted content.

DisplayPort is the first A/V interface to rely on packetized data transmission, a form of digital communication also found in PCIe, Ethernet, and USB. Unlike earlier A/V systems, where the signal channels relied on a separate clock signal to coordinate the image, the DisplayPort protocol is based on small data packets known as micro packets, which can embed the clock signal within the data stream. This gives DisplayPort the ability to deliver very high resolutions, or even transport multiple images, over the various twisted pairs inside a single interconnect assembly. In a world where extended desktops and multiple monitor installations are quickly becoming the norm, this is an enviable performance advantage.

VESA unveiled DisplayPort version 1.2 (also identified as DP++) on December 22, 2009. This improved standard increased the bandwidth of the connection, and its dual-mode nature improved its compatibility with HDMI and DVI-D by allowing the source device to process the signal internally and output TMDS content through a passive cable connection. This was just the performance advantage the system needed for widespread industry adoption. In January 2013 an additional improvement was made to the DisplayPort Dual-Mode standard which further improved compatibility with Ultra HD and D4K image technology.

Today DisplayPort technology is making fast and furious inroads into the industry. A study by the International Data Corporation (IDC) shows that DisplayPort was on 5.1% of commercial desktops and 2.1% of commercial notebooks in 2009. They predict that market share will grow to 89.5% for commercial desktops and to 95% for commercial notebooks by 2014. Additional market penetration of up to 31.6% combined annual growth rate through 2017 is also anticipated.