Hello, can you see this?

https://dell.to/4b8r343

(page 122)

Respectfully,

@DELL-Young E​ no, unfortunately I am not able to access this page.

Hi,

I am not able to open her link, too.

The Dell U.2 Enablement Kit (P31H2) is designed to allow the use of U.2 NVMe SSDs in the Dell PowerEdge R730xd server. The kit consists of a PCIe controller card and four SFF-8643 cables that connect the U.2 drives to the controller card. Regarding the PCIe slot requirements, the search results indicate that the enablement kit should be installed in a full-length PCIe x16 slot, not an x8 slot.  Using an x8 slot may result in reduced performance, as the U.2 NVMe drives require high bandwidth.The large heatsink on the enablement card is likely necessary to dissipate the heat generated by the PCIe-to-U.2 controller chip and associated circuitry, rather than for bifurcation purposes. Bifurcation, which splits a single PCIe x16 slot into multiple x4 slots, is handled by the server's BIOS and does not require a specialized heatsink. 

In summary, the Dell U.2 Enablement Kit (P31H2) should be installed in a full-length PCIe x16 slot on the Dell R730xd to provide support for U.2 NVMe SSDs. Using an x8 slot may result in reduced performance. The large heatsink is necessary for the controller card itself, not for the bifurcation functionality.

This link seems to be interesting, too.

https://dell.to/3JyI3ov

@Dell-Martin S​ Thank you very much! 
Regarding the linked video: it seems like they are installing the card at riser 1. Are there different variants of this riser because at my machine these are all x8?

And what does this PCIe-to-U2 controller chip do? I once had a direct u.2 to PCIe adapter and there was no heat sink at all. The PCB was rather slim.

Hello,

This is the link Young was sharing

NVMe expander page 121 - removing a card from riser 2

Owner manual

https://dell.to/3WgCkLw

I do not see any documentation that it can be installed an any other riser but riser 2, slot 4, x16.

Then you use the cable, which is four cables, to connect expander to backplane.

The video seems to show they are installing PCIe drive not the expander card.