AMD launches new cable

Waiting for us when we arrived at work this morning was AMD’s latest piece of hardware. It is something that the company is incredibly excited about, and that it believes will accelerate the uptake of its Eyefinity multi-display technology.

The product in question is this, a low cost Displayport to HDMI adaptor. The reason AMD is so excited about it is that it reduces the cost of entry for triple monitor setups.

To understand why, one needs to know a little bit about display connectors. HDMI (High Definition Multimedia Interface) is designed to carry both video and audio signals. One of the reasons that it has enjoyed a rapid uptake on PCs is that the video component of HDMI is the same as DVI. This makes adaptors feasible and is the reason that modern laptops have D-Sub VGA connectors and HDMI ones rather than having DVI connectors.

Of course, as we have encountered in the past, HDMI is subject to some pretty stringent licensing regulations. In order to put HDMI onto a device, its manufacturer needs to pay the HDMI licensing body, which it doesn’t have to do if it uses D-Sub, DVI or Displayport.

This lack of licensing requirements is one reason why AMD in particular has gone for DIsplayport to drive its multi-monitor cards. But there is also an electrical reason why Displayport is the preferred connector.

DVI (and HDMI) signals require an external clock generator. This is a piece of electronics that creates a timing signal, or ‘clock’, that is used to keep various integrated circuits in sync. Each display driven by HDMI or DVI needs a dedicated clock generator, and on the current range of AMD RADEONs there are two clock generators. This is enough for two displays, but in order to run more displays AMD runs into a problem to which it sees Displayport as the solution.

This is because Displayport generates its clock internally. By doing away with the need for external clock generators AMD is able to support a number of displays that is limited only by the space on the back of the card.

The problem is that while AMD is deeply in love with Displayport, monitor manufacturers aren’t. Actually finding a screen with Displayport is difficult enough, but there is the added insult of such monitors costing a premium over ones that just have DVI and HDMI.

Until now the only solution to the problem has been to use ‘Active’ Displayport to HDMI adaptors. These need to be powered in order to generate a clock signal, and all this extra hardware has made Displayport to HDMI adaptors prohibitively expensive. This in turn has stifled the uptake of AMD’s Eyefinity technology.

By releasing a new adaptor that doesn’t need to be powered AMD has managed to bring the cost down by a huge amount. Which is why the company is so excited over a bit of plastic coated wire with plugs on it. Whether or not this will be enough to get the masses using three or more monitors is a whole other question, but at least the solution is much, much cheaper than it was in the past.

Running more than two monitors from a RADEON card used to involve a mess of adaptors. This example is from MSI's booth at Computex this year.