I'm running my rig on Ubuntu server with 5 Sapphire Nitro+ RX580's, trying to locate longer PCIE power cables but not easy to find in my area. As I do have one more RX580 not mining at the moment. Anyways back to my thought. So does this mean it is better to mine with Windows over Ubuntu? I am also getting roughly 19.38 Mh/s per card. Does flashing the GPU bios help with the hashrate in Ubuntu? Or is this mainly a Windows thing to do only? I could flash each card in my Windows machine but will those setting then work when I move it back to the Ubuntu rig? I'm using the AsRock H110 Pro BTC+ board. I also read somewhere where don't remember where but will look for it again that I can undervolt with a command in Claymore. Can you confirm this?