Try searching the board for MirrorFolder, it has an operating mode where it uses a Filter Driver to replicate changes in a RAID-1 like fashion. It works at file rather than block level (which means you can make it mirror only part of a filesystem hierarchy), but thanks to the filter driver approach it only mirrors actual changes: ie, 1 byte modified in a 10gig file only causes that one byte to be updated, not the entire 10gig file being synced1.
Other than that, I dunno. You might want to google "RAIDCore", but I'm not sure that runs without a hardware adapter.
#1 - to be pedantic: of course you get a full sector update since that's the smallest addressable unit on a harddrive.