Intel Rapid Storage Tech and RAIDing PCIe NVMe SSD cards

[JJohn29]

Hi All,

We purchased an ASUS Z170 Pro Gaming motherboard and two Intel 750 PCIe NVMe 400 GB SSD cards with the intent to RAID1 the cards using IRST. We upgraded the firmware of the cards and the BIOS. However, we do not see the cards in IRST, which always says, "No disks connected to system". We can install any OS we want to the drives and they will boot. The BIOS sees the drives. But the IRST in the BIOS does not. We tried all of the HOWTOs we could find online. We found a video showing someone from ASUS appearing to do RAID0 with the same cards and an ASROCK Z170 Extreme7+, so I ordered that board to try it. However, the drives still do not show. The comments regarding that video suggest the drives in the video are connected using U.2. Other HOWTOs show people using M2 drives. Is the problem with IRST or with the board? Or is this just not possible with PCIe NVMe cards?

Thanks for your help,

John

[JJohn29]

nestor_intel,

Thank you so very much for your answer. I did not realize that the PCIe card slots would bypass the PCH and go directly to the CPU, whereas the M.2 slots on the boards go through the PCH first. This makes a lot more sense.

I wish it were such that this were better documented. Every site I see talks about "RAIDing PCIe drives". These sites talk about PCIe slots and M.2 slots as if they are they are the same, but obviously they are not. It also makes me wonder what to make of those PCIe cards with M.2 slots on them. I presume those also skip the PCH.

Will this at any time change? If I buy a new machine in a year's time with the latest Intel chip/chipset, will I be able to RAID these cards using the IRST from the BIOS? I ask because we will likely buy a server at that time and would need to decide if we use cards like the ones I have or if we should buy drives with U.2 connectors.

Thanks,

John

[idata]

duperon,

The features for the Intel® Rapid Storage Technology come in the BIOS option ROM, basically if it can't be done in BIOS it can't be done in Windows*.

This means it is related to the motherboard design limitation or you may check in the future with the OEM for the motherboard.

Let us know if you still require any other assistance from us.

[JJohn29]

nestor_intel,

Your statement, "The features for the Intel® Rapid Storage Technology come in the BIOS option ROM, basically if it can't be done in BIOS it can't be done in Windows*." is incorrect.

The point of this whole discussion and that which lead to my confusion was that the IRST is part of the chipset, and that drives attached to motherboards via the PCIe slot communicate directly with the CPU, skipping the chipset. The problem was not that the drives were not seen in the BIOS (they were) or that they could not be used in Windows (they could, Linux too, my target OS). The point was only that IRST will not see any drives connected via PCIe slots but will if one uses an M.2 or U.2 slot. That is a very important distinction which most on the Internet do not seem to know and it looks like even your people are just figuring it out.

I was just wondering if there would be a way around this limitation in the future. This is likely a stupid question to ask as the design of PCIe is such that it will always skip the chipset. If so, future boards are likely to have U.2 slots in abundance which then replace the SATA ones.

If you can't confirm/deny that, then you can just consider this issue closed and thanks for your help.

[idata]

duperon,

We understand your position, about the limitations in the future, this is something we cannot comment or know at the moment.

Thanks for replying back.

[idata]

duperon,

We would like to know if you still require any assistance from us?

Thanks.