The majority of motherboard raid is software based meaning it requires drivers and functionality to be built into the OS... A true RAID setup is dependent upon a controller, im yet to see a motherboard raid capable of RAID 5+1 with hot swapping
Motherboards which indicate a RAID controllers often have simply a standard disk controller with a BIOS extension implementing RAID in software for the early part of the boot process. A special operating system driver then takes over the raid functionality when the system switches into protective mode.

Show me motherboard RAID that works well in Windows95 or 98