Intel RST Raid Lost when SATA Set from RAID to ACHI and Back

[Tularis]

Hello,

I believe I have found a serious problem with the Intel RST RAID controller.

I've create a RAID5 Array of 4 HDDs.
But When the SATA controller is placed from RAID - AHCI and the PC reboots then placed back to AHCI all RAID Configuration is lost... so I am left with 4 "Non-Raid" disks....

Steps to recreate :
 
Create RAID Volume
Reboot and change SATA from RAID (Intel RST Premium) to AHCI
Reboot and attempt to load windows
Reboot and change SATA from AHCI to RAID (Intel RST Premium)
All Disks are now no longer in a RAID Array...


This has come about because my PC had a BSOD and then failed to boot so the mother board reset to default values and booted windows. This caused me to lose my 16TB Raid Volume.

Is this a failure of the Motherboard or the Intel RST... I can't really now create a new volume in case this happens again. Anyone have any ideas?

Motherboard: Z170X-G3 (F21)
GPU: Intel Core i7 6700K
Mem: 2x 16GB DDR4-2400
GPU: Nvidia 1080

[Tularis]

Some Further Testing. - The issue is not related to letting the OS Load.
 
Create RAID Volume
Reboot
[BIOS] Set SATA from RAID to AHCI
Reboot - DO NOT LET OS LOAD
[BIOS] Set SATA from ACHI to RAID
Reboot - DO NOT LET OS LOAD
Raid 5 Failed Missing 2 HDDs
 
After this is don't think I will ever trust Intel RAID.

[shadowsports]

Loss of an array can be an unfortunate side effect of a BIOS reset.  Typically however, the BIOS does not load set up defaults unless it is upgraded, has a weak or dead battery, or a failed overclock has occurred.  Were you trying to OC CPU or Memory?

[Tularis]

Hey Shadowsports,

Recently I've been seeing a few BSODs, when that happened the PC failed to reboot correctly and the BIOS came up and said the boot failed and the bios should be reset.
The only overclocking I did was to enable XMP on the RAM which took it from 2500mhz to 3000mhz (I Think)...

I've done a full mem test and I've run Prime 95 for 2hrs with no faults...

However:

I can replicate the RAID issue when I don't have any BIOS errors just by switching the SATA from RAID to AHCI and rebooting (without loading the OS) This seems to be a major failing of the IntelRST (Or this implementation). The controller seems not be able to detect all RAID disks after being toggled from RAID to AHCI and back...

I think this issue related to the disks changing their numbers (Or perceived location to the BIOS) as my NVMe was Disk0 and now its Disk4 and when you toggle the SATA from RAID to AHCI and back they are different numbers again. (The disks in the SATA Ports remain the same)

To me this seems like a bug that needs to be addressed.