***(This is a copy of a question posted to Linus Tech Tips without any reply)

I recently sustained a HDD crash as a result of the dreaded Seagate ST3000DM001 curse. I had no idea that this model was voted "most likely drive to self-destruct." Luckily, most of the data (but not all) was backed up to my Netgear ReadyNAS 312. This situation did give me an excuse to build another computer, since my home computer was getting old.I thought that it would be a good idea to have an internal RAID 1 system for my data drive and a Samsung 970 EVO plus as the boot drive. The motherboard is an ASUS ROG Z490 Maximus XII. The data drives are two Seagate IronWolf Pro 4 TB units. I am not familiar with setting up RAID systems, but from the information I've read, you can set up a RAID 1 volume either at the ASUS motherboard BIOS level using the INTEL Rapid Storage Technology (IRST) system hardware controller on the motherboard or set up a RAID 1 "Mirror Disk" under Windows 10 Disk Management software. I have tried it both ways, and neither system seems to recognize the disk data of their counterpart. My question is which system is more reliable? This is my primary objective. I don't need the disk striping speed of a of a RAID 0 or 5 or 10, nor do I need heavy duty number crunching ability. I just want an extra layer of security before the NAS.