I'm running Windows 10 Pro on an AMD 5900X system with X570 motherboard. Windows was installed on an NVMe SSD (Samsung 980 Pro) and then two other SATA drives for data. Motherboard set to AHCI from the outset.
I now wish to add 2 new drives for data in a motherboard raid 0 config and keep the pre-existing drives accessible. When I install these and switch motherboard SATA setting from AHCI to RAID, Windows boots fine (NVMe drive unaffected by the switch) but the two pre-existing drives are no longer visible to it.
I have tried making the change to RAID and then booting into safe mode (with bcdedit) to try and trigger a switch from AHCI to RAID drivers - no luck.
Have confirmed that all drives (new and old) are visible to Windows in AHCI mode. I am specifically looking for motherboard RAID 1 rather than a Storage Spaces solution. Grateful for any advice.