Raid5 - sm951/950pro Z170 OC Formula ?

RAID arrays of PCIe SSDs is a new, cutting edge capability that is not at all mature yet IMO. We've only had it officially with the Z170 chipset and the IRST 14.5 and 14.6 drivers.

I've never used or heard of a RAID 5 of three PCIe SSDs. I'm leaving out the detail of the PCIe SSD being AHCI or NVMe.

I have used a two drive AHCI SM951 RAID 0 volume, and a handful of ASRock Z170 board users have posted in this forum about their two and three drive AHCI SM951 RAID 0 volumes. All we know about PCIe SSDs in RAID comes from our experience and discussions in this forum.

I can tell you several useful things about PCIe SSDs in RAID arrays that may help you make your decision.

If you've used Intel IRST RAID with SATA drives, the PCIe SSD support is not quite the same. It is not as simple as using SATA drives in RAID. For example, once PCIe SSDs are in a RAID 0 array, the drives will not be listed/shown anywhere in the UEFI/BIOS or System Browser tool. They will only be shown in the IRST utility that is an option in the UEFI.

In Windows, the RAID 0 array is recognized fine, and is shown normally in the IRST Windows program. Single PCIe SSDs are not displayed in the IRST Windows program.

TRIM instructions are passed to SSDs only in RAID 0 arrays. That was a major feature when it was released a few years ago. No progress since then, so no TRIM for SSDs in RAID 5, RAID 1, and RAID 10. Unhappy

That of course is a major issue with long term performance.

To get the ability to create a RAID array of PCIe SSDs, you must install the SSDs and boot the PC, or go into the UEFI. You must then restart the PC in order for options in the UEFI to appear that allows you to use the PCIe SSDs in a RAID array.

The most significant issue with the current RAID support for PCIe SSDs IMO is they cannot even survive the POST process if their configuration settings in the UEFI are changed.

After performing a UEFI clear or update, and going directly into the UEFI UI (Windows did NOT boot), results in the RAID 0 array being broken. That does not happen with SATA drives in RAID arrays, as I have seen many times. Resetting the configuration for the PCIe SSDs in RAID 0 in the UEFI, and restarting the PC does not bring the RAID 0 array back. It must be recreated and any data or OS on the SSDs is lost.

The last UEFI update for my Z170 Extreme7+ board seemed to attempt to keep the non-default UEFI settings to preserve the RAID 0 array. The SATA mode remained as RAID, and a critical option was added to the Storage Configuration screen that is normally and still is found elsewhere. I may be wrong about the intent of all this. Regardless, nothing changed.

RAID 5 might be able to rebuild itself in theory, but I would not depend on that without trying it.

Keep in mind that all this is based upon the Intel IRST driver and UEFI Option ROM, and will be the same on any manufacture's mother boards. I imagine things will improve as the IRST driver is updated, but that takes time.

About your bonus question, you can SLI on this board with three PCIe SSDs. The Z170 chipset now provides the interface for the Ultra M.2 slots. None of the processor's PCIe 3.0 lanes are used. But each Ultra M.2 slot is shared with two SATA ports. Using three M.2 SSDs means zero Intel SATA III ports available.

Good luck with your RAID 5 question. I'd like to know that myself.

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dirac99 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 02 Nov 2015 Location: atlanta Status: Offline Points: 3	Post Options Post Reply Quote dirac99 Report Post Thanks(0) Quote Reply Topic: Raid5 - sm951/950pro Z170 OC Formula ? Posted: 02 Nov 2015 at 9:36pm
	Can someone confirm that it is possible to use 3 sm951 or 950 pro drives in raid 5 on the Z170 OC Formula motherboard? (bonus question - can you still do SLI?) I plan to get the i7-6700 Don't want to order all of this until I know it's possible.
	-bob

parsec Members Profile Send Private Message Find Members Posts Add to Buddy List Moderator Group Joined: 04 May 2015 Location: USA Status: Offline Points: 4996	Post Options Post Reply Quote parsec Report Post Thanks(0) Quote Reply Posted: 03 Nov 2015 at 3:08pm
	RAID arrays of PCIe SSDs is a new, cutting edge capability that is not at all mature yet IMO. We've only had it officially with the Z170 chipset and the IRST 14.5 and 14.6 drivers. I've never used or heard of a RAID 5 of three PCIe SSDs. I'm leaving out the detail of the PCIe SSD being AHCI or NVMe. I have used a two drive AHCI SM951 RAID 0 volume, and a handful of ASRock Z170 board users have posted in this forum about their two and three drive AHCI SM951 RAID 0 volumes. All we know about PCIe SSDs in RAID comes from our experience and discussions in this forum. I can tell you several useful things about PCIe SSDs in RAID arrays that may help you make your decision. If you've used Intel IRST RAID with SATA drives, the PCIe SSD support is not quite the same. It is not as simple as using SATA drives in RAID. For example, once PCIe SSDs are in a RAID 0 array, the drives will not be listed/shown anywhere in the UEFI/BIOS or System Browser tool. They will only be shown in the IRST utility that is an option in the UEFI. In Windows, the RAID 0 array is recognized fine, and is shown normally in the IRST Windows program. Single PCIe SSDs are not displayed in the IRST Windows program. TRIM instructions are passed to SSDs only in RAID 0 arrays. That was a major feature when it was released a few years ago. No progress since then, so no TRIM for SSDs in RAID 5, RAID 1, and RAID 10. That of course is a major issue with long term performance. To get the ability to create a RAID array of PCIe SSDs, you must install the SSDs and boot the PC, or go into the UEFI. You must then restart the PC in order for options in the UEFI to appear that allows you to use the PCIe SSDs in a RAID array. The most significant issue with the current RAID support for PCIe SSDs IMO is they cannot even survive the POST process if their configuration settings in the UEFI are changed. After performing a UEFI clear or update, and going directly into the UEFI UI (Windows did NOT boot), results in the RAID 0 array being broken. That does not happen with SATA drives in RAID arrays, as I have seen many times. Resetting the configuration for the PCIe SSDs in RAID 0 in the UEFI, and restarting the PC does not bring the RAID 0 array back. It must be recreated and any data or OS on the SSDs is lost. The last UEFI update for my Z170 Extreme7+ board seemed to attempt to keep the non-default UEFI settings to preserve the RAID 0 array. The SATA mode remained as RAID, and a critical option was added to the Storage Configuration screen that is normally and still is found elsewhere. I may be wrong about the intent of all this. Regardless, nothing changed. RAID 5 might be able to rebuild itself in theory, but I would not depend on that without trying it. Keep in mind that all this is based upon the Intel IRST driver and UEFI Option ROM, and will be the same on any manufacture's mother boards. I imagine things will improve as the IRST driver is updated, but that takes time. About your bonus question, you can SLI on this board with three PCIe SSDs. The Z170 chipset now provides the interface for the Ultra M.2 slots. None of the processor's PCIe 3.0 lanes are used. But each Ultra M.2 slot is shared with two SATA ports. Using three M.2 SSDs means zero Intel SATA III ports available. Good luck with your RAID 5 question. I'd like to know that myself.