[Disclaimer: not a TrueNAS question, yet I’d appreciate some help from those of you with some knowledge of Intel hardware.]
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?
I think you will get a much better answer from the ASRock Forum.
I’d like to help you but I have zero experience with Oculink.
When you do ask for help there, include more specific hardware information, specifically the make/model of the NVMe drives and the make/model of the oculink cables. I can see that this could be crucial in solving the mystery.
Thanks. I did, indeed, post my issue in the ASRock forums–it’s the first thing I did, as a matter of fact, though I figured I’d get a faster response here or on Reddit.
Certainly seems as though you have made the correct configuration changes to the BIOS howewever, its worth noting that according to the manual, only 1 of the 2 oculink ports on that board are PCIe Gen 4 (the other is PCIe Gen 3).
The AliExpress cables are probably the lowest hanging fruit here, have you checked the NVME drives directly in the boards NVME slot?
You’re going to have to put one of the drives in there anyway if you want Gen 4 speeds on both drives.
What is the actual adapter connecting the Oculink cable to the M.2 card?
I completely agree with this statement. You get what you pay for and if you purchased 8TB NVMe drives, do not go cheap. All your data will be using this hardware, do what you can to prevent failure.
I saw that as well in the User Manual yesterday. This should not make a difference, the Gen 3 port will run the NVMe at the lower speed.
Someone opined that the cables might be at fault, and suggested that I go the U.2 route, namely buy Oculink to U.2 cables, and then U.2 to M.2 adapters instead. My question is, wouldn’t that bottleneck my drives to U.2 speeds (which, afaik, are less than 10Gbps)?
The opinion that seems to be emerging in the STH forums is that my current setup does not power the drives. It appears that the Oculink connector does not provide any power, so it may be that I need to find a different way to power the drives. On the other hand, why would anyone even manufacture Oculink to M.2 adapters like these that do not provide any power inputs?
Perhaps their are Oculink cables with power intake cables. Somewhat like some SATA drive cables use motherboard SATA connector, but also include power in cable connector.
I actually thought that power might be the problem. But, my knowledge of Oculink is very limited.
That is interesting, I just checked into it, Oculink does not provide power. This means that the M.2 adapter “should” have a power connector to work, otherwise how do they expect you to use the thing?
If you cannot locate a power connector, I’d return them, then grab the right stuff.
Interestingly, the guy that sells these Oculink to NVMe M.2 adapters on eBay seems to be of the opinion that Oculink does provide 3.3V power. See this post for details.
AFAIK power delivery is not part of the oculink standard. I have only ever used adapters with supplemental power, like this. Never had any issues with that type of adapter.
Interesting, thank you! So whose fault is it that “standard” Oculink cables do not work? Here are the possibilities as I see them:
It’s ASRock’s fault, for not implementing the proper Oculink standard in their mobo connectors; my guess is that modifying the cable in the way described ends up supplying power through the Oculink cable, hence powering up the NVMe M.2 drives; also, the Supermicro cable does nothing but add power to Oculink in a roundabout U.2 fashion;
It’s everybody else’s fault, and ASRock is the one that designed their mobo connectors properly.
Edit: I didn’t bother analyzing the modifications required in any detail, but I’d be curious if they target exclusively the power side of the equation, or do they also mess with some of the data pins?
Good question… but please define “standard OCuLink cable”.
Because, if I read SFF-9042 correctly, A1/A21/B1/B21 are “reserved” and not intended to be wired: The Supermicro cable does not wire these pins, and the mod involves cutting these wires. So which one is “standard” here?
As I read the standard document, OCuLink has no power lane. The table in Figure 1 of the wiki post shows no power lane. If a M.2 drive gets power from this cable, it must actually be powering itself through interface lanes.
Reading the wiki article, it’s not clear where the incentive was found to cut B13 and solder it to ground B14. But I assume it must be examination of the (obviously directional) Supermicro CBL-SAST-0956.
I would rather trust Supermicro to implement standards correctly. More so than cheap shops selling plainly wired (An → Bn) extension cables where the standard is more sophisticated.
The AsRock Rack motherboard is supplied with a breakout cable to 4*SATA. Is there an official accessory cable from AsRock Rack for PCIe devices?
