I do not know what the complications from your Matrox might cause but the specifications on the Quadro 5000 are as follows:
"Maximum Display Resolution Digital @ 60Hz 2560x1600 - See more at: http://www.nvidia.com/object/product-quadro-5000-us.html#sthash.0eSY67M9.dpuf"
So it cannot do it. Now the newer K series cards will do it and much less expensive for instance the GTX 780 has 4096 x 2160 maximum resoution.:
thanks Bill, It's a beautiful Card. I knew it was around 2560 scan rate. But was hoping that there might be a "fix" for it. I guess the fix is another new card. We paid around $1750 for the thing, hoping that it would last a couple of years. Who knew 4K would change everything. I think from now on, I'll go with the cheapest, no frills card that will work. I'm really getting tired of how fast this stuff becomes obsolete.
Is there any good technical reason go with the Quadro line?
Well, at the time we purchased it, it fit very well with Adobe products for fast or no rendering.
In Prem Pro CS6.0.5 I rarely get a red line, meaning render this. It seems to chew right through it.
For rendering out to Blu Ray and DVD's in Encore the combo of the 5000 and Matrox MX02 Rack with MAX,
greatly speeds up the process.
The Geforce 700 series or Titan cards currently give 4K output via HDMi or displayport. However until the 800 series cards come with HDMI 2.0, 30 frame is max for HDMI and displayport uses MST currently. I suggest waiting on the HDMI2.0 cards since a 4K I/O card such as Blackmagic 4K Extreme is not an option.