NVS 810 on 16 Displays


I need a little help. It was my understanding that I could use (2) NVS 810 cards in one computer to drive 16 displays for a 4 x 4 wall. I finally got the wall built and the displays hooked up (16 Vizio 65" 4k tvs) but I’m only seeing 8 displays. I’m using Display Port to HDMI adaptors that are all the same. The displays that show up are from both cards, so I know both cards are working. Can someone please tell me what I might be missing?

Thanks for any help or suggestions you can give me.