@Sebastian I need to look into something I found over the weekend. I installed Linux Mint 19.1 on a test Dell computer that was in uefi mode and had raid-on mode configured. LM 19 installed correctly and ran. There was some strangeness with the network adapter so I reloaded LM in bios mode. But then it hit me, why was LM working in uefi mode…?? I need to find out if the linux kernel developers addressed the Intel Raid controller issue in Raid-On mode.