Are you installing the 850 EVO in a RAID config (striped or mirrored)? ...or just trying to use JBOD?
RAIDing SSDs is a waste - you won't gain any performance, and may in fact lose some performance.
As far as RAID drivers go, it's not the SSD drivers you need, it's the RAID controller on your MB (or the attached card) that you need. It's also possible that you just need to enable the extra controller, that some boards have, in BIOS.