It works as you say in structures that do not contain an active switch chip, but here there is a pcie switch, the configuration can be done differently. The card I put the link to supports 32 u3 disks. But it has only 3 ports, it is not clear how the cable connections will be.
Multi-NVMe (m.2, u.2) adapters that do not require bifurcation
- Thread starter andrewbedia
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Presumably, you have to use switches to connect more drives.
But don't buy tri-mode. They tend to just expose the NVMe drives as if they were SAS drives. Performs worse because you don't get the NVMe software stack. They have a few advantages, like being guaranteed* to support hotplug regardless of motherboard support, but overall it's mostly worse than a normal NVMe adapter.
*if you use intermediate switches that don't support HP, then you might not get HP capabilities.
correct
Table 4: NVMe Device or PCIe Switch Direct-Attach Options Supported for Each Adapter
The guide says 'Up to sixteen x1, eight x2, or four x4 NVMe direct-attach drive support' on page 10. I assume direct-attach means nvme stack. Does it work? Is it fast enough?
High point with their FHFL double wide x16 carrier board for 16xM.2 drives
https://www.highpoint-tech.com/pr/highpoint-revolutionizes-high-density-aics-with-the-ssd7749m2
Now they just need to release the JBOD version for ZFS enthusiasts ...
https://www.highpoint-tech.com/pr/highpoint-revolutionizes-high-density-aics-with-the-ssd7749m2
Now they just need to release the JBOD version for ZFS enthusiasts ...
The datasheet talks about RAID Support: Single, RAID 0, 1, 10. I assume by Single drives, they mean JBOD.
Has anyone seen a U2 SSD PCIE adapter (for optane sized drives that can be mounted *ON* the card) that uses one of these switches, i can't find anything quite like that (i have a space constrained server i would like to use one in) i can only find ones that require bifurcation support on the motherboard.
Sorry for asking a question I know you already answered, but I just read this entire forum and can't think clearly anymore
Even though of the site it says pcie3.0 it can use 4.0 if your system has it available? I'm pretty sure it's yes, but want to double check before I buy one right now. Thank you for posting this, I've been pissed debating what to do because I upgraded to a b760 from my old z87 without check bifurcation and now using it 95% of the time for proxmox and have no need for a GUI. Anyways thank you guys for all the info, I really appreciate it.
Even though of the site it says pcie3.0 it can use 4.0 if your system has it available? I'm pretty sure it's yes, but want to double check before I buy one right now. Thank you for posting this, I've been pissed debating what to do because I upgraded to a b760 from my old z87 without check bifurcation and now using it 95% of the time for proxmox and have no need for a GUI. Anyways thank you guys for all the info, I really appreciate it.
Buy what? Many cards are mentioned in thread
And as a rule of thumb, you can always use lower PCI-E standard cards in motherboards with newer PCI-E slots,
just at slower speed.
In case that wasn't clear from the last reply, it only has to do with the PCIe standard, it doesn't have anything to do with the card's chipset or bus speed. You can safely buy any card you want.
If you get a PCIe 4.0 capable motherboard, any PCIe 3.0 card you use in it will work at PCIe 3.0 speeds, but there's no question whether or not it will work at all. It'll absolutely work.
Conversely, the opposite is also true: if your motherboard only supports PCIe 3.0, and you put a PCIe 4.0 card in it, it'll work at PCIe 3.0 speeds. No question that'll work, too.
How about bifurcation on a supermicro motherboard? Can I mix PCIe 3 and 4 drives on a PCIe 4 16x slot with motherboard 4x4x4x4x bifurcation? Will they all work at PCIe 3 speed or will they each work at their respective max supported speed?
Will I be able to run U.3 disks (Micron 7400 Max) on the U.2 x16 4-port (PLX PEX 8747) card?
From what I've found, U.3 disks are backward compatible with U.2 ports. But not the other way around, a U.2 disk does not work in a U.3 port. Does this also apply when using an adapter with a switch chip, like this?
From what I've found, U.3 disks are backward compatible with U.2 ports. But not the other way around, a U.2 disk does not work in a U.3 port. Does this also apply when using an adapter with a switch chip, like this?
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I do that currently. Mixing NVMe gens on a carrier device is okay and they will report as independent devices, as you'd expect. To achieve the best performance you should define the PCIe link as Gen 4 and not utilize the Auto Determination option. If the board should be left to auto determine the Gen speed then it is a possibility the link will be set lower.
This advice is true for other motherboard vendors as well. When possible, you should define the PCIe Link speed manually instead of Auto.
I've been looking at this card: https://www.aliexpress.com/item/1005005671021299.html (recommended in this thread).
You can get cables that split a single SFF 8654 connector to two SFF 8639 connectors to connect to the U.2 drives. That gives you up to 8 with this card. If you can take advantage of a PCIE 4.0, there is also two port PCIE 4.0 version that would allow 4 U.2 drives.
I was about to ask if there's a PCIE 4.0 version of the 4 port card as I've been unable to find any, and also where does one get the cables as they get pretty expensive.