ASUS TUF SABERTOOTH Z97 MARK 2 and Razer Tiamat 7.1

Good day! I bought myself an ASUS TUF SABERTOOTH Z97 MARK 2 (http://www.ulmart.ru/goods/783978), but it is still on the way. I also want to order a Razer Tiamat 7.1 and temporarily (3-4 months) connect it to the built-in sound system. The mother supports 7.1 (8 channels), but on the back of the panel there is no gray connector, instead of it there is some kind of polygon, although the tiamat has a gray 3.5mm plug. What is this polygon and will it work acceptable?

Rear panel photo:
Spoiler