Does the Dell R820 or R920 support PCIe bifurcation?

Hello

I don't think any servers prior to the latest 14th generation support configuration of slot bifurcation. You can review the available BIOS options in the system manual on the support page.

http://www.dell.com/support/

I only saw Precision workstations in the system list for that card. 80G5N is a better part number for that card.

Thanks

Technically R820 does support bifurcation but only under a very specific set of conditions.

As seen with the PCIe adapter card which is part of the NVME backplane solution supporting U.2 2.5" drives, there is a PCIe card with 4 ports x 4 lanes. 

In theory, there would be a method of adapting this card to M.2 drives. 

Have a look at the product code(s) YPNRC 22FYP or 

DELL PCI-E SAS BRIDGE CARD FOR DELL POWEREDGE R720 R820 

I noted the PCIe Ultra Speed adapter does not work. However, the above drive bay solution does work.