NVIDIA Surround - Accessory Display

Hello everyone,

Good day. I have questions regarding NVIDIA Surround. I want
to accomplish 3x1 surround configuration with an “accessory display” (fancy way
for a fourth monitor outside the surround configuration). Currently I am only
able to get the 3x1 surround working. If I decide to use each display
separately, all 4 works. I want this configuration, so that I can game (3x1) and
in the other one watch movies and stuff.

My PC specs goes as follows:

CPU: Intel I7-3770K, Motherboard: Asus Maximus V Extreme,
RAM: Corsair 32GB DDR3, Video Card: 2XSLI Giga-Byte NVIDIA GeForce GTX 980 4GB

OS: Windows 10


**Do I need an additional video card to accomplish this?
If not, what am I missing from the following configuration?**

I appreciate your help. Kind regards.

Note: I apologize for my bad English. I am still learning.