Can we use two Xavier NX link with PCIE X4,one as host and another as slave

Hi Navidias,

Can we use two Xavier NX link with PCIE X4,one as host and another as slave.how to config?

Yes. It is possible to have this configuration. But, a cable/special connector is required to connect (back-to-back) the PCIe interfaces on each board.
Also, you may have to flash the target that you want to operate as PCIe endpoint mode with the ODM data 0xB8191000.

we will use backboard to link host and slave PCIEX4.what is the link speed Gen4 or Gen3.Can we choose the link speed when the backboard can not run to gen4.

By default it will try to take the link speed to Gen-4. In case if you are not confident of the electricals and want to operate the link at a lower speed, you can modify the property ‘nvidia,max-speed’ to set whatever the speed you want in the DT entry of the root port system.