What is the result of connecting a single link (DVI-D) video source to a dual link monitor?

[Jarod Wilson]

On 10/14/2009 09:07 PM, Alex Hewitt wrote:
> Shawn O'Shea wrote:
>> On Wed, Oct 14, 2009 at 5:37 PM, Alex Hewitt <hewitt_tech at comcast.net
>> <mailto:hewitt_tech at comcast.net>> wrote:
>>
>>     I'm trying to connect a new Mac Mini to a Barco monitor. The Barco
>>     monitor expects a dual link video source (2048 x 1536 /1536 x
>>     2048) but
>>     the Mini is outputing single link DVI-D. The Mac sees the monitor as
>>     having a resolution of 1280x1024. Apple makes a dual link DVI adapter
>>     but I don't know if this will allow the Barco to work properly. Anyone
>>     have any experience with this kind of setup?
>>
>>
>> Single-link DVI has less pins/wires and maxes out at 1920x1200
>> resolution. For higher resolutions, you need the extra wires and can
>> go to 2560x1600. You need to also make sure that the DVI cable you are
>> using is dual link as well.
>> Pictures of connector types:
>> http://www.interfacebus.com/Design_Connector_Digital_Visual_Interface_DVI_Bus.html
>> Discussion of single vs dual with resolution information:
>> "WHAT ARE SINGLE AND DUAL LINKS ?" section of
>> http://www.datapro.net/techinfo/dvi_info.html
>>
>> -Shawn
>>
>>     The Mac Pro does have a dual link video but I'm not sure if that
>>     system
>>     would also have the same problem. The Barco site only describes MS
>>     Windows systems and provides drivers for the same.
>>
>>     -Alex
>>
>>     P.S. BTW, we did connect a Totoku 3MP display (2048x1536) which uses a
>>     DVI-D connection and that display worked at full resolution.
>>
> Thanks Shawn. Good pointers. There is something a bit odd about this
> though. The Totoku monitor is running at it's native resolution
> (2048x1536). The Mac gives me the full resolution as a choice in the
> display preferences. I'll look closely at the connector (miniPort to
> DVI-D) and see if it's actually dual link. The DVI-I dual link is
> definitely not working.

 From http://www.apple.com/macmini/specs.html

# Extended desktop and video mirroring: Simultaneously supports up to 
1920 by 1200 pixels on a DVI or VGA display; up to 2560 by 1600 pixels 
on a dual-link DVI display using Mini DisplayPort to Dual-Link DVI 
Adapter (sold separately)


-- 
Jarod Wilson
jarod at wilsonet.com