What Is Rail-Optimized NIC Placement?_
In GPU clusters the scale-out network is partitioned into parallel rails, each rail carrying traffic for a subset of GPUs without cross-rail forwarding inside the rack. NIC placement is chosen so that the PCIe links and cabling map each GPU to the correct rail switch port. This mapping is fixed at rack integration and remains independent of the intra-rack NVLink copper fabric.
Technical Details
Each NIC port is cabled to a separate leaf switch that belongs to one rail; MPO connectors are used for the fiber runs to the scale-out fabric. The assignment is verified against the OEM rail diagram before any structured cabling begins. No torque screws are applied to the push-pull connectors. The same placement rules apply whether the fabric is InfiniBand or Ethernet.
How Leviathan Systems Works with Rail-Optimized NIC Placement
Field crews confirm NIC-to-GPU rail alignment during rack assembly and before structured cabling to the leaf switches; mis-mapped ports are corrected at commissioning.
Related service
Network Testing & Commissioning →