12G SFF-8643 cables and U.2...?

digity

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Jun 3, 2017
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I have U.2 NVMe 2.5" SSD drives. I'm looking to get the Icy Dock U.2 NVMe 5.25" to 4 bay enclosure which has 4 x SFF-8643 connectors. I'll connect those with a 4 port SFF-8643 to PCI-e 3.0 x16 card. The problem is, all SFF-8643 cables I see available are listed as up to 12G mini-SAS. I know NVMe PCI-e 3.0 x4 is up to 32 Gbps. Are these the right SFF-8643 cables for NVMe connections? If so, will I get up to 12 or 32 Gbps? If those are not the right cables, what are the right cables??
 

i386

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Mar 18, 2016
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Check the icydock website, they added a list of compatible cables and adapters after users started reporting that the cage didn't work as expected.
 

digity

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Jun 3, 2017
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Check the icydock website, they added a list of compatible cables and adapters after users started reporting that the cage didn't work as expected.
Interesting. The official SFF-8643 to SFF-8643 cables also say 12G. I guess I can ignore the 12G part...?
 

itronin

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Nov 24, 2018
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in a SAS SFF-8643 cable there are Qty 4 SAS channels at at 12Gbps each. Lots of wires. all get used for those 4 channels Aggregate is 48Gbps...

U.2 uses lots of wires too in fact they all (I'm pretty sure, except maybe sideband) get used making the nvme connection.

I've used both Generic SAS 8643 to SFF-8643 cables to make NVME backplane connections as well as magic/secret sauce SM NVME white connector SFF-8643 cables to make NVME backplane connections. And then I tried the magic SM white connetor SFF-8643 to connect SAS drives. As soon as I did that little pixies flew out of the cable and smacked my hand with rulers.
okay no that did not happen. worked just fine.

YMMV but I'm gonna leave this sitting on the cable. Hopefully nothing wrong with experimenting in the lab right? :p
 
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