[Simon Murphy]

I was given the response below as to why it has been removed.
I’m disappointed as we used it everyday. We already use both DVID outputs on our Mac Pro’s and were using the Extended Desktop on a LCD tv.

Thank you for contacting us. Yes, with the latest driver update we have
removed the extended desktop feature. In a nut shell it was not supported in
other O.S. Like Vista and Windows 7. On the Mac side there are now less
expensive and better solutions like dual DVID outputs. That is why the
extended desktop feature has been removed.