T5820 PCIe Questions

Hi all,

A few quick questions about the 5820 workstation. Mine has a Intel Xeon W series chip.

Is there any official documentation of the PCIe bifurcation available? People here and there talk about being able to split slot 2 into four x4 lanes for NVMe drives but is there any official docs on this? What about the other PCIe slots, i.e. does slot 1 support bifurcation? How about the lanes used for the flexbay NVMe drives?

Has anyone had any experience using the PCIe lanes exposed out of the SFF 8643 connectors? The fact they can be used with NVMe drives makes me thing they are just standard PCIe x4 outputs as described in the SFF 9402 reference guide (or maybe the SFF 8613 connector and SFF 9401, I'm not entirely clear on the difference between the two as they seem to be identical). However, the OEM flex-bay adapters appear to have a FPGA on board and a relatively complicated interface board which makes me think there may be something else going on in there. Again, does anyone have resources to explain this? The workstation manual is very light on specific information.

Any help would be appreciated.