Let us revive this oldest message here in the forum.
I used dual display on X1K. It worked. Not as swell as a Mac, but worked.
X5K only has 1 PCIx16 slot for big graphics cards but we do have other slots... PCIeX1 and X4.
Wondering.... as I just found out they make adapters that allow PCIeX16 video cards in x1 and x4 slots...
How about using 2 Radeon 7750 in the X5K?
One using the PCIeX4 slot and this adapter?http://www.orbitmicro.com/global/pexp16 ... -4568.html
Or a x1 to x16 here:https://www.amazon.com/StarTech-com-Exp ... B0039XPS5W
Slower but may be fine for every day office use graphics.