Multi-NVMe (m.2, u.2) adapters that do not require bifurcation

[ca3y6]

I don't even understand whats the purpose of having lanes configuration for a single x16 slot

That allows you to convert a x16 slot in say four x4 slots. x4 is typical for a U.2 or M.2 nvme SSD, so with the relevant adapter, it allows you to connect 4 devices on a single x16 slot. The question is whether that conversion from x16 to four x4 is done by the motherboard (ie bifurcation, which then requires only a very cheap adapter, but only server motherboards typically have that feature) or it is done by the adapter itself (PCIe switch, like mentioned earlier in this thread, much more expensive adapter)

nor whats the purpose of slapping a second x16 slot on the board if it's electrically x4 no matter what?

Because if you have, say a x8 card like an HBA, you cannot physically make it fit in a x4 slot, the extra pins of the card will prevent it from slotting in. With a x16 slot (with 12 inactive pins), at least you can physically plug this HBA. It will only work at x4 speed but it will work.

 

[alaricljs]

Alternative - check your x1 slots for open ends (not likely) and install single x4 or x1 m.2 adapters in those. You already said it's not so much about the performance.

(The x4 adapter if you could use one would be the more future proof choice... But x1 cards are cheap, so does it matter?)

 

[luckylinux]

Because if you have, say a x8 card like an HBA, you cannot physically make it fit in a x4 slot, the extra pins of the card will prevent it from slotting in. With a x16 slot (with 12 inactive pins), at least you can physically plug this HBA. It will only work at x4 speed but it will work.

Thankfully some Manufacturers on some Models (NOT all Manufacturers on all Models though) started making open-ended Slots for that Reason, so you don't need to but off the plastic End of the Slot anymore, if you want to do that (I never did so far).

Too bad it's not standard Practice .

Anyway, that doesn't prevent the Manufacturer stuffing CMOS Battery or PCH Heatsink at the end of the Slot, which will prevent / make it harder to install a longer PCIe Card anyways .

 

[nexox]

Because if you have, say a x8 card like an HBA, you cannot physically make it fit in a x4 slot, the extra pins of the card will prevent it from slotting in. With a x16 slot (with 12 inactive pins), at least you can physically plug this HBA. It will only work at x4 speed but it will work.

Open-ended x4 slots exist and will fit an x8 HBA, but x16 are the only ones that can provide the full 75W power and the clip to physically support a.GPU. I don't know why you would put a GPU on the chipset lanes, the answer is probably related to why I don't buy MSI products.

 

[ca3y6]

I don't know why you would put a GPU on the chipset lanes, the answer is probably related to why I don't buy MSI products.

Not saying I would, but perhaps if you would only use the video hardware encoding features which hardly require any power or bandwidth.

 

[luckylinux]

Not saying I would, but perhaps if you would only use the video hardware encoding features which hardly require any power or bandwidth.

To be fair the Chipset PCIe Slot isn't necessarily always *that* Bad.

A PCIe 3.0 x4 Chipset connection gives you 32gbps of Bandwidth, which is plenty for even a dual Slot 10gbps NIC, 25gbps NIC would be a bit on the Edge.

Not 100% sure, but I believe that is full duplex, i.e. you should be able to Receive Data (IN) from the NIC at 25gbps and still write to an Array of SATA Drives (OUT) for instance. Or alternatively read from an Array of SATA Drives (IN) at 25gbps and send Data (OUT) from the NIC at 25gbps.

So, while I do agree it's not PCIe 4.0 x16 that gives you ~ 256 gbps, it's still pretty good Performance for many Applications IMHO.

You might even get the GPU in a "very light" Application using a x1 Adapter (like those that are e.g. used for Mining).

 

[schlangz]

Thanks everybody that cleared things up perfectly.

I won't get the PCIe adapter for multiple drives, but instead get one regular passive PCIe-NVME adapter for one of the older drives.
And then another 2,5" drive adapter for the other old NVME drive which I'm going to connect to the internal SATA controller.

 

[nexox]

And then another 2,5" drive adapter for the other old NVME drive which I'm going to connect to the internal SATA controller.

I don't believe there are any SATA to NVMe adapters, you may be looking at a carrier for a SATA m.2 drive.

Edit: your best bet is probably a USB-NVMe adapter, which you can connect to a motherboard USB header to make an internal drive.

 

[schlangz]

Oh no. There are a gazillion USB-NVMe adapters why nobody made a NVMe-SATA adapter?

 

[nexox]

Oh no. There are a gazillion USB-NVMe adapters why nobody made a NVMe-SATA adapter?

USB is designed to encapsulate other protocols, SATA is not.

 

[schlangz]

In that case I will use one of these? Let me see if I can find a proper adapter for that

 

[schlangz]

That one should do the trick right

CERRXIAN 2 x 19-poliger auf Dual-USB-3.0-A-Adapter, Desktop-Motherboard 19/20-poliger Prot auf Dual-USB-3.0-Buchse, PCBA-Flach-Typ: Amazon.de: Computer & Zubehör

CERRXIAN 2 x 19-poliger auf Dual-USB-3.0-A-Adapter, Desktop-Motherboard 19/20-poliger Prot auf Dual-USB-3.0-Buchse, PCBA-Flach-Typ: Amazon.de: Computer & Zubehör

www.amazon.de

 

[beatle]

That looks about right. Then you just need an NVMe to USB enclosure and a means to secure the drive inside the case. Velcro or zipties should suffice.

 

[schlangz]

Thanks everybody you saved me a lot of money and hassle

 

[kryten]

Can't speak for whichever model you have, but I had the gen3 4x SFF-8643 model. It definitely didn't have hotplug implemented correctly. It seemed to only have one hotplug slot when it should have had one for each downstream port.

If you can boot into Linux, do a `tree /sys/bus/pci/slots` and check `/sys/bus/pci/slots/*/address` to see which ones correspond to what. If you can't, then you can check in hwinfo64 and you should see something like this for each port:
View attachment 44066

You also need BIOS support for hotplug events. Fortunately, Thunderbolt has forced most manufacturers to start supporting hotplug events.

Have you come across a card that has hot plug on all slots yet?
I haven't seen a PCIE4 card yet

 

[mattventura]

Have you come across a card that has hot plug on all slots yet?
I haven't seen a PCIE4 card yet

I haven't bought one, but I believe the best options would be some of the higher-end HighPoint cards and Broadcom's inhouse cards (pure PCIe switches, NOT tri-mode). Both of those advertise both hotplug and backplane management support.

Theoretically, the serialcables.com card with external ports that I have should also work for this, but I haven't been able to do anything useful since it apparently uses a non-standard pinout.

 

[kryten]

thought so, just hard to justify the cost.

 

[panchovix]

Hello there, sorry to necro. Does someone know if there's a switch that does X4 to X2X2 but PCIe Gen 4? I'm finding some ASM2812 cards that do PCIe X4 to X2X2 but Gen 3.

 

[Mithril]

If any of the Gen4 stuff is affordable yet I'd also love to know (any) to (any)2x or 1x as well

Also if anyone has seen any gen4/5 with the downstream being only Gen3 that could be interesting

 

[klosz007]

On Aliexpress I already saw PLX88024-based cards which are not that expensive (~200USD). PCIe 4.0 x8 to 4x M.2 PCIe 4.0 (x4 I think). This might be the early birds of PCIe 4.0-enabled switch cards.