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

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ca3y6

Active Member
Apr 3, 2021
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No I am talking about U.2 HGST SSDs connected with cables, they do not get powered by the card, they get powered by a sata/molex connector. Also tried through an intel backplane (connected to the caecent card) which gets powered by an ATX connector (picture below). So I don't think the problem is power. And also those HGST drives work fine on the same system using PCIe bifurcation.

But yes, cooling is a challenge. I resolved it with having big noctua fans blowing directly into the drives, keeps them under 45 deg celcius even with the fan at low speed.

4192AA16-94E9-4457-AAC0-9B1D72D2D916.jpeg
 
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axemar

New Member
Feb 8, 2025
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Hi,

I have a Dell R340 that does not support PCI bifurcation. It has a riser putted on the PCI x16 (works on x8) and gives x16 (x8) and x8 (x4).
Unraid is installed on it and I want to add 2x SSD cache with a PCI slot to get arround 2 to 3gb/s on the x16 (x8) riser slot.
I want to add a PCI SFP+ 10gb/s on the x8 riser slot (x4).

Is this card could work ? without bifurcation : https://www.aliexpress.us/item/3256805299547807.html

Thanks
 

soupyfrood

New Member
Dec 12, 2019
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I’d love to know if anyone else has found some cost-effective quad cards. I’d love to able to run 4 drives on a 4.0 x8 slot.
 

Aqualung

New Member
Jun 30, 2024
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I’d love to know if anyone else has found some cost-effective quad cards. I’d love to able to run 4 drives on a 4.0 x8 slot.
M2 NVMe PCIe 4.0 cards are still very expensive. PCIe 3.x should do just fine.
 
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soupyfrood

New Member
Dec 12, 2019
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I use the U.2 version of this card:

https://a.aliexpress.com/_Ey9KiD4
Odd, the link doesn’t work for me. What chip does it use?

M2 NVMe PCIe 4.0 cards are still very expensive. PCIe 3.x should do just fine.
Well yes but no. I don’t want to put four 4.0 x4 drives behind 3.0 x8. 4.0 drives are pretty cost-effective these days. Of course, your point that connectivity is expensive is true. If the only option is one of the $1000+ PCIe 4 switch cards, then it no longer makes sense.
 

Aqualung

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Jun 30, 2024
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Well yes but no. I don’t want to put four 4.0 x4 drives behind 3.0 x8. 4.0 drives are pretty cost-effective these days. Of course, your point that connectivity is expensive is true. If the only option is one of the $1000+ PCIe 4 switch cards, then it no longer makes sense.
Here ya go: $470 second hand. But if you're using it for a 10GbE NAS, PCIe 3.x should do, and you can get much better deals for PCIe 3.x.
 

RolloZ170

Well-Known Member
Apr 24, 2016
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Link is 404, it almost looks like it tried to load and then redirected to a 404, wonder if the listing is pulled :(
not avail. in your area(customs issues)
anol4pe08
 

Mithril

Active Member
Sep 13, 2019
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Odd, the link doesn’t work for me. What chip does it use?


Well yes but no. I don’t want to put four 4.0 x4 drives behind 3.0 x8. 4.0 drives are pretty cost-effective these days. Of course, your point that connectivity is expensive is true. If the only option is one of the $1000+ PCIe 4 switch cards, then it no longer makes sense.
In *most cases* you'll be limited by the actual flash performance (or higher level things like file system, CPU/RAM, OS) in real world use. Basically anything but the sequential pure read and pure write with hand picked transfer size and queue depth the manufactures use to put the number on the box. I'd bet money that on average a decent enterprise Gen 3 drive would smoke the pants off the average consumer gen 4 or 5 drive in real world use outside of "see how fast this single large file copies".

One of the things I need to refresh my memory on is how these handle "over subscription", if you say have 4 drives sending 4x3.0 each how well does the switch chip handle that. I feel like someone here did some testing on one of these cards (maybe not this specific switch chip however).
 

Mithril

Active Member
Sep 13, 2019
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not avail. in your area(customs issues)
anol4pe08
Ugh, 404 is a really dumb way to handle that IMHO.

Actually, maybe a short link issue. Loading the main site and searching for that card I get the listing and can open it lol
 

mattventura

Well-Known Member
Nov 9, 2022
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If you have the 404 issue, try changing your country to a different region. I changed mine from USA to Spain and it let me see it.
 

kryten

Member
Apr 10, 2023
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Im using a Ceacent controller for NVME drives. is there a reason when plugging in a drive it doesn't auto detect it, every time i plug and unplug a drive you have to scan bus in device manger.
 

mattventura

Well-Known Member
Nov 9, 2022
628
326
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Im using a Ceacent controller for NVME drives. is there a reason when plugging in a drive it doesn't auto detect it, every time i plug and unplug a drive you have to scan bus in device manger.
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:
1749874364598.png

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

kryten

Member
Apr 10, 2023
87
14
8
Yeah mine the same as yours, i have 2 though. bus 4 and 8
Cheers for the help, there's always something.
 
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