I notice that my asrock BTC won't boot if not connected to monitor. I need only 1 monitor for the whole mining rig though.
So I just want to make sure.
With my ASRock BTC, I have never use a dummy plug. But I use nVidia cards. It seems dummy plug was used only for previous generations of AMD GPUs. With ASRock BTC and nVidia, you plug you screen directly to the motherboard.