Originally Posted by solipsism
It’s ONE-WAY. Any source coming from a DP/mDP port can output to a device that receives HDMI/DVI. Going from HDMI/DVI to DP/mDP isn’t native to the DisplayPort specs. Or are you saying that choose to implement the output from their Macs to HDMI HDTVs, despite your insistence that the spec is not compatible, only the cable itself is compatible?
I speculated that they may have this wrapped up nicely to not only send HDMI/DVI signaling out, per the spec, but also receive them, since Apple uses the same port for both input and output. This would have been nice, but it’s obviously not what they have designed, now that we have testing done to confirm it.
There have already been several detailed posts from multiple sources explaining the situation very clearly. My only concern is that the posts that you continue to make will just add to the ongoing confusion surrounding the iMac's support for video input/output.
Here is what is certain.
Pass through of other video standards (i.e. DVI/HDMI) is possible under the DisplayPort spec. However, in order for this to work the device manufacturer must
include support for this feature within the device itself. Pass through can work for either input
(given the necessary support within the device). Without such support, you need an external, active video converter to make DisplayPort compatible with either DVI/HDMI or VGA. This latter seems to be the approach that third-parties are talking to enable either DVI or HDMI input
into Apple's DisplayPort-equipped products (such as the 24" Apple Cinema Display and -- apparently -- the new 27" iMac).
The costs for said converters run upwards to $200 (DVI to Mini DisplayPort input) to a reported $400 to enable HDMI input from a PS3 to Apple's 24" Cinema Display (the latter requires both a converter and scaler). We don't know yet how much the input
converts will cost for the new iMac, but from all current tests and analysis it appears that they will be fairly expensive (combining both an HDMI signal converter and a high-resolution scaler in an external box).
In any case, if you have a device (like any currently made -- new -- Mac) or a PC with a video card that directly supports DisplayPort then you should be able to connect that device to the iMac's Mini DisplayPort input
with a simple cable or adapter (and fairly cheaply). Also, the existing output
adapters from Apple and several third parties should continue to work with the new iMac.