In order for this to work you must follow each step exactly or windows will fail to see your raid array as a bootable device and the setup will fail to boot from your raid array.
- Enter your motherboard UEFI bios.
- Go to Advanced > AMD PBS
- Enable "NVMe Raid mode"
- Go to Advanced > RaidXpert2 Configuration Utility (in some cases you may need to F10+save and reboot before it will show up as an option)
- Warning! Going beyond this point will delete any data on your NVMe drives
- Once in the RaidXpert2 management, go to array management > delete array
- select the drives you want to use for the new raid array and choose "Delete Array(s)"
- Now choose Create Array select enable for the drives you want to raid with the correct raid type and your preferred configuration, then click create.
Download the AMD Raid Drivers from here: AMD Drivers and Support for Radeon, Radeon Pro, FirePro, APU, CPU, Ryzen, desktops, laptops
extract the drivers to a usb drive, preferably the same drive that you use for installing windows 10 pro.
Now insert your windows 10 pro install media and start the setup process.
Now install raid drivers from the file you extracted to your usb in this order:
Once you do this you can install windows like normal and it will boot from the raid.
That's it now you're done.