motherboard probably ASUS P8Z77-V PRO
and graphic card ASUS ENGTX560 DCII TOP/2DI/1GD5
Yes, my earlier answer about the motherboard applies. Only 2 display at the same time but it will be disabled once you put a graphics card into the PCIe slot.
And since you have an nVidia 5XX, you can only use 2 display at a time. Only 6XX series of nVidia can display more than 2 on a single card.