Samsung 950pro gets invisible after switching SATA-Mode to RAID

Cheers guys,
i have built a new system containing a Samsung 950 pro: Gigabyte GA-Z170X Gaming-7 with Intel i7-6700k.
I got the NVMe SSD working (cloned via Samsung Data Migration Tool from my old Corsair Force 3) while having SATA-Mode in UEFI set to “AHCI”.
Having 2 WD Blacks which i always had in a RAID-1 I wanted to switch SATA-Mode to “RAID”.
As i switch SATA-Mode to RAID, the 950pro gets invisible and cannot be used anymore.
Today I tried to do a clean UEFI Win10 Install (SATA-MODE RAID) but the NVMe SSD wasn’t visible in Windows Setup. ( I thought I will not need any drivers, as Win10 has basic NVMe drivers on board)

Does anyone have a hint, why the 950pro works well in AHCI, but disappears when switching to RAID, so that even Win10 Setup doesn’t see the drive anymore?
Thx for any advice,

best regards, Chris.

I just went through the hair pulling exercise where the Samsung 950 Pro disappears…

In short, all your drives should be in GPT/UEFI mode; if one of them is in legacy MBR/BIOS mode the Samsung disappears especially in RAID mode;
as the Intel RAID ROM and Samsung MBR/BIOS compete for boot supremacy.

See my posting in this thread:
[Guide] How to get full NVMe support for Intel Chipset systems from 6-Series up (24)
POST #356 & #358 which details the fun and games of GPT/UEFI and MBR/BIOS not playing nice together.

Also use the latest Samsung driver
Recommended AHCI/RAID and NVMe Drivers
Samsung NVMe driver v1.4.7.16 WHQL:

You should sort yourself in short order; after I spent about 8 hours “spelunking the depths of the bios” to figure this one out…

Cheers
Hans

@ Reservoirdog:
Hello Chris,
welcome at Win-RAID Forum and sorry for the late reply!

It probably has something to do with the boot sector data.
I hope, that hancor’s reply helps you to solve your problem.

Merry Christmas and a Happy New Year!
Dieter (alias Fernando)