I have Asrock H81 Pro BTC, chipset Intel H81, and only 3 GPU and the same error.
The sistem work with 2 GPU, but CODE 12 error with 3 GPU.

http://i.imgur.com/7wiGECO.png


http://i.imgur.com/NbpYMjH.png

It did work sometimes after several restarts.
I tried on Ubuntu 14 and the same. The system see only 2 GPU, so I belive it has something with the BIOS.