Why do PCIe SSDs work in x1 mode?

Question

Samsung

Supermicro SYS-510P-WTR platform, X12SPW-TF board, Intel Xeon Silver 4314 processor, two Supermicro CBL-SAST-0817 wires (SAS X8 LA to 2x Oculink X4 Internal 36CM 34AWG).

4x Samsung 980 Pro SSDs are inserted into 4x U2 ports via an M2-U2 adapter with x4 bandwidth.

All SSDs are displayed "linked as x1" and give speeds in the region of 2Gb / s. What could be the problem? If in an adapter, which one would you recommend?

Answer 1

If I understand correctly, then you have an adapter connected to 4 PCI-e lines and 4 slots are occupied by SSDs in it?
Then it turns out that the smart adapter correctly "spread" the available 4 lines, 1 line for each slot. And what else can you do, how else to hang 4 disks on 4 bus lines? I will assume that the adapter can develop full speed (if it is smart and dynamically switches lines) with one SSD.
To connect 4 SSDs at full speed, you need the adapter on the second side to have PCI-e x16 (I don’t know if such exist in principle)