I have the ASRock H110 Pro BTC+ motherboard running 13 Nvidia GTX 1070's and they are experiencing a similar problem where they do not want to hash higher than 27 MH/s. Would you mind sharing the BIOS mod that you are using to achieve higher hash rates? I previously ran 8 of these same 1070's on an ASUS B250 Mining Expert motherboard and they had no problems performing at 32 MH/s. I realize that each motherboard is different and requires understanding. Any information you can share will be greatly appreciated.