M17xR4 w/1TB SSD - to RAID or not to RAID

I just upgraded to a Samsung EVO850 with Win10Anniversary. Not a trouble free upgrade but everything is now working. I left the mSATA 64GB SSD in place but with all the upgrade issues I removed the RAID0 but left the 64GB drive in place. The question to the experts is: "Is there any reason to use the mSATA device in a RAID0. If yes, why and how do I get the RAID setting back to what they need to be. If No, should I just remove it or can it be left in place ad set up as a recovery drive or what should I do with this thing? Also, when I boot the 1TB drive is listed as drive0 and the mSATA is drive3 and does not show up in the WIN directory listing. Also, in BIOS RAID is still listed in the Advanced section, if I change this to AHCI with the mSATA now show up as Drive X in the directory listing. RAID in a m y s t e r y to me.