Hello thanks for choosing Dell.

https://dell.to/3NWySzN

Figure 15. Cable routing – 24 x 2.5 inch NVMe drive backplane

You need a card for NVME as well as the cable connected as you can see from the link above. Hope this helps.

Thank you for the response. The diagram you referenced shows connections for the NVMe cards to the backplane expander. I don't see those connections on my backplane expander, which seems to connect only to a mini PERC.

Hello lsputman,

This should be the backplane:

Part #:PC8TD

Part Desc.:ASSY,CRD,BP,24X2.5,N,R740XD,V2

Assembly Card Backplane, 24X2.5, NVMe, V2

I attached an image.

Thank you, Charles. 

My current configuration looks like Figure 13 in the link that @DELL-Young E provided above. After looking through the documentation some more, it looks like it would involve some significant fiddling to get to the 24x NVME configuration (different backplane + cabling, different riser configuration in the back since there's rear storage there now). I guess the main question is whether the currently installed backplane supports *any* NVMe drives (with the addition of an expander card on the one open x16 slot).

Appreciate the help!

Thanks--appreciate the help. SAS or SATA it is!