Dell H755 with generic 4 port nvme(2x8654 8i) backplane, cable problem.

[ghzgqx]

Hello, I have a dell H755 PCIE raid controller in a whitebox EATX server case with 4 nvme + 8 sas direct connect backplane. I will not use the sas port but use the nvme port.
I first try to use it with PCIEx16 to 2x 8654-8i adapter board, connect with two 8654-8i cable, and enable slot bifurcation x4x4x4x4 for test, the in UEFI I can see all 4 U.2 SSDs.
Then I unplug that adapter, install H755, and connect H755 to backplane with 8654-8i LP to 8654-8i cable, then in controller's UEFI config menu, no PDs display, all count is 0.

BP and 8654LP-8654 cable photo is attached below.

I try sas mode with some sata/sas ssds with 8654-8i LP -- 2x8643 cable, it works well so the controller works.

What should I do next to make nvme work?


Maybe: nvme pinout is not standard OR nvme mode required a "controlled" backplane to communicate to enable?
Just want to raid these U.2 disks.

 

[i386]

Is this a u.2 backplane? Or u.3?

U.3 backplanes/connectors work only with u.3 ssds while u.2 backplanes/connectors will work with u.3 in compatibility and u.2 in native mode.

nvme pinout is not standard

Nvme is a protocol on top of pcie, for pcie there are different connectors and cable standards.

 

[ghzgqx]

Is this a u.2 backplane? Or u.3?

U.3 backplanes/connectors work only with u.3 ssds while u.2 backplanes/connectors will work with u.3 in compatibility and u.2 in native mode.

Nvme is a protocol on top of pcie, for pcie there are different connectors and cable standards.

I am sure it is U.2 because:
The server case seller said it is U.2 and not U.3
I connect it to PCIE - 8654 adapter board and insert a Intel P3500 U.2 SSD and it works in pciex4

 

[mattventura]

I don't recall the exact commands, but can you try `storycli /c0 show profile` (assuming it's the only LSI/Broadcom controller in the system)? They have different "profiles", one supports SAS/SATA only while the other is tri-mode.