Please help: NVMe drives on Oculink not detected!

[Aqualung]

I got a NAS system built around an EC266D2I-2T/AQC motherboard. I purchased two 8TB NVMe M2 drives, and I have installed them in the Oculink slots (OCU1 and OCU2) using two Oculink to NVMe adapters. So far it looks like the system is not detecting them. What am I doing wrong? My guess is that there are some BIOS settings that I need to mess with in order to get them detected, though at this point I don’t really know what those settings are exactly.

At this point I have the following settings:

OCU Mode Selection = PCIE (as opposed to SATA)
SATA Controller = “Disabled” (as opposed to “Enabled”)

Are these the right choices? If yes, what am I doing wrong?

(And here is the mobo manual.)

 

[bugacha]

Try different cable?

Supermicro 55cm OCuLink to U.2 PCIE with Power Cable (CBL-SAST-0956)

Copper Cable Assembly OCuLink SFF-8611 (x4) to U.2 SFF-8639 with 4 Pin Power Cable OCuLink Storage Expansion Supermicro Certified

store.supermicro.com

 

[Aqualung]

Try different cable?

Supermicro 55cm OCuLink to U.2 PCIE with Power Cable (CBL-SAST-0956)

Copper Cable Assembly OCuLink SFF-8611 (x4) to U.2 SFF-8639 with 4 Pin Power Cable OCuLink Storage Expansion Supermicro Certified

store.supermicro.com

Thanks. I guess I should have specified that my NVMe drives are M2.

 

[bugacha]

Thanks. I guess I should have specified that my NVMe drives are M2.

That doesn't change the problem.

 

[Aqualung]

That doesn't change the problem.

At any rate, the link you posted is not the right type of cable.

[Edit] These are the cables I got.

 

[bugacha]

At any rate, the link you posted is not the right type of cable.

[Edit] These are the cables I got.

read online about OCUlink and ASrock - its common issue that you're seeing, lots of people complain and its all down to the cables.

By the looks of it, SM cable is working.

For your case, just buy U.2 to M.2 adapter and you're done.

 

[Aqualung]

For your case, just buy U.2 to M.2 adapter and you're done.

Thanks. Wouldn't this bottleneck my drive throughput to U.2 speeds though? (I need to squeeze out at least 10Gbps from my drive to saturate my 10GbE NAS network connection.)

 

[etorix]

U.2 and M.2 are form factors, not protools, and do not have throughput limits.
If anything, a U.2 drive is likely to perform better than its M.2 counterpart, due to better cooling.

 

[Aqualung]

@etorix, @bugacha:

1. I am guessing that the power connector that comes with the Supermicro cable does not need to be used in my scenario, right?
2. Would this be what you had in mind when speaking of a U.2 to M.2 adapter?

Many thanks for the advice!

 

[Sean Ho]

Both U.2 and m.2 drives still need 5v [3.3v + 12v] power, whether from Molex (as in the SM cable) or 15-pin SATA power.

Yes, that or any number of similar cheap U.2/m.2 adapters should work.

 

[etorix]

I am guessing that the power connector that comes with the cable does not have to be used in my case, right?

It absolutely has to be. And that could be the explanation of your issue: Your OCuLink to M.2 adapter has no power input.

 

[bugacha]

Thanks. I guess I should have specified that my NVMe drives are M2.

Another option, try to email ASrock and ask them what cables do they recommend.

I got given this email : asrockrack_eu@asrock.nl when I had problems with fan RPM speed on W680D4U-2L2T/G5
They did reply and gave me a new unreleased version of BMC to try out.

 

[Aqualung]

Both U.2 and m.2 drives still need 5v power, whether from Molex (as in the SM cable) or 15-pin SATA power.

Thanks. Should I understand that the Oculink cable actually provides power as well? And I say that because I do not see any power connectors on the Oculink to M.2 adapters!

[Edit:] @etorix may have answered this one already.

 

[Aqualung]

It absolutely has to be. And that could be the explanation of your issue: Your OCuLink to M.2 adapter has no power input.

So why would anyone even manufacture this adapter in the first place? What would it be for? (Is there such a thing like "power-over-Oculink"?)

 

[Aqualung]

So I went ahead and ordered one of these. What do you guys think, will this work? (Note that I also ordered the gear for the U.2 detour, but I might send that back if the Oculink to M.2 board works.)

 

[etorix]

At the very least this one would rule out power issues…

So why would anyone even manufacture this adapter in the first place? What would it be for?

A cynic would say that it's manufactured to sell, not manufactured to work…
As for adapters which works with certain cables but not others, we've seen an "interesting" situation in the MJ11-EC1 thread with the SFF-8564 connectors. I'm sure there subtleties and/or non-standard compliant parts with OCuLink as well.

 

[BlueFox]

Both U.2 and m.2 drives still need 5v power, whether from Molex (as in the SM cable) or 15-pin SATA power.

Yes, that or any number of similar cheap U.2/m.2 adapters should work.

Neither M.2 nor U.2 use 5V at all. M.2 is 3.3V only and U.2 is 3.3V and 12V (though primarily the latter).

 

[etorix]

Reference documents for SFF-8611/8612 connectors do not provide pin definitions but refer to SFF-9042. Which then designates OCuLink as "SFF-8621", for which I can only retrieve a non-final draft. I'm no electrical engineer, and the whole thing looks clear as mud to me.
But having 3.3V and 5V power on "reserved" pins with "NO WIRE" in the "Cable" column of the various tables of the SFF-9042 document doesn't look good.

Of course, the planned but not delivered optical version of OCuLink would not carry any power but just data.

 

[Aqualung]

@BlueFox, @etorix, @Sean Ho, @bugacha: interesting development: I asked one eBay seller of Oculink to NVMe adapters such as this how the drive gets its power, and here's what he said: "There is no need to power for ssd separately, use OcuLink's own 3.3V PCIE power supply." Go figure!

 

[Sean Ho]

Neither M.2 nor U.2 use 5V at all. M.2 is 3.3V only and U.2 is 3.3V and 12V (though primarily the latter).

Thanks for the correction!