InfiniBand NDR/XDR naming refers to whole-port rate, not per-lane rate

NDR is described as '400 Gb/s' and XDR as '800 Gb/s', but these are whole-port figures. The per-lane rates are 100 Gb/s and 200 Gb/s respectively. Confusing per-lane and per-port rates leads to 4x errors in bandwidth calculations.

InfiniBand speed nomenclature (NDR, XDR) refers to the total per-port bandwidth, not the per-lane rate. NDR = 400 Gb/s per port = 4 lanes x 100 Gb/s. XDR = 800 Gb/s per port = 4 lanes x 200 Gb/s. This is similar to how PCIe Gen5 x16 refers to the total bandwidth of 16 lanes, not the per-lane rate.

Always check whether a bandwidth figure is per-lane or per-port. For InfiniBand, the convention is per-port. For NVLink, the convention in this repo is per-link (per-lane). When comparing InfiniBand to NVLink, ensure both are using the same convention.

This naming confusion is a common source of errors in bandwidth calculations. The repo's existing infiniband-xdr record was corrected for this exact issue. The key insight is that NDR and XDR are port-level designations, not lane-level.