PCIe Bifurcation on Xavier NX, Nano, and TX2 NX

[user149303]

Hello,

I am looking to design a single board that can accommodate the Xavier NX, the Nano, and the TX2 NX. I want to have multiple NVMe SSDs connected to PCIe ports on the board to obtain as much expanded memory as possible. As far as I know, the greatest number of PCIe lanes that is common to all three is x2. I am looking at putting a PCIe switch on this board to bifurcate the x2 PCIe into at least two x1 PCIe ports and then connecting the NVMes to the x1 PCIe ports. My questions are:

1. Will each Jetson support this kind of PCIe bifurcation?
2. Are there any special considerations in terms of compatibility that will have to be taken into account when designing this board?

[Trumany]

Please refer to the interface comparison doc for detail info. https://developer.nvidia.com/jetson-tx2-nx-interface-comparison-migration-da-10170-001-v10pdf

Jetson TX2 NX supports two PCIe Gen2 interfaces at the module pins: One x1 lane interface and one x2 lane interface. Jetson Nano supports a single x4 PCIe Gen2 interface. Jetson Xavier NX supports one x1 lane and one x4 lane interface.

Regarding the “bifurcate x2 into two x1”, we have no recommendation. It seems a switch is necessary, maybe you can check with the vendor of such switch.

[user149303]

Thank you for the information.

To clarify on the bifurcation question, are the Jetsons able to recognise and interface with multiple devices that are connected to a PCIe switch?

[Trumany]

No dedicate design for this. For PCIe port of Jetson, you can refer to the design guide for the design of Jetson side.

[user149303]

Ok, thank you for your help.