Goal: Duplicated writes to two identical drives, just for hardware failure protection. Single speed or (double speed striped) reads from both simultaneously (I almost don't care at this point).

I don't want to use a software raid because I need to support windows / linux dual booting in a semi-safe "lower level" way.

Using a mobo's RAID 1 should be a fairly straight-forward process, but I'm concerned about a warning I see everywhere.

The phrasing always seems to be of the form: "A mobo is almost always using a FAKEraid which more often than not will work with windows 10, but may fail with other OSs because it's primarily is a firmware sleight-of-hand masquerading as a hardware RAID."

Ok, this is silly. A simple RAID 1 on two identical SATA III drives should not be that complicated. Dual-speed reads (not important), and single-speed but duplicated writes at the lowest possible level.

Or is it still "above" the level of, say, an LSI card?