Please keep in mind RAID 0 does NOT work well with Samsung 950 PROs. You can't install the Samsung NVME driver and you won't be able to use or access Samsung Magician.
On the Asrock X99 board, at least, once you enable RAID support on the SATA connections the NVME is no longer recognized. To use the Samsung 950 Pro as a boot device, I had to use the SATA ports as AHCI and then just use software RAID via windows.
I was not attempting to RAID the NVME drives but 4 other Sandisk Extreme Pro SSDs.