Another bump of this thread - I've picked this board up recently. It came with BIOS 1401 from 2013 which supports Ivy CPUs but it won't actually post from a cold boot, I have to hold down the power button to shut it off and then power it back up. It then won't actually show anything (my monitor will light up "black" so receiving a signal apparently) until it reaches Windows. It also won't seem to accept RAM beyond 1333MHz, which is annoying as I have 8GB 2133MHz RAM in their!
I probably should have just got a retail board (I didn't know it was an RM motherboard!)
I'm going to try flashing the standard P8H61-I LX rev 2 BIOS on it to see what happens.