General AOCs are not offered
NVIDIA states that AOCs are not offered for the native 100G-PAM4 InfiniBand / Ethernet series, citing connector weight, installation risk and modern AI data-center scale.
INFINIBAND NDR · MEDIA SELECTION
InfiniBand NDR: Optics vs AOC vs DAC by Reach and Topology
For NDR, media selection is not a generic distance ladder. The exact Quantum switch, ConnectX / DPU endpoint, connector shell, port mode and NVIDIA-supported interconnect determine which path is valid.
DACShortest links · low power · direct electrical path
Native OpticsConnectorized fiber · longer reach · scalable fiber plant
AOCDo not assume native availability for 100G-PAM4 NDR
TopologySwitch-to-adapter, switch-to-switch and breakout differ
NDR is 400 Gb/s class100G-PAM4 interconnects use four high-speed lanes per 400G endpoint.
DAC is the short-reach baselineNVIDIA documents straight DACs at 0.5–2 m and splitter cases up to 3 m.
Native AOC assumption is unsafeNVIDIA's current 100G-PAM4 guide does not offer general native AOCs.
Optics scale fartherUse pluggable transceivers + connectorized fiber where the topology requires it.
Media Decision
Choose by endpoint, reach and service model
The ranges below are planning boundaries from current NVIDIA LinkX documentation, not universal limits for every NDR part number.
DAC / SHORTESTInside-rack / very short linksLowest-power direct copper path. NVIDIA documents 0.5–2 m straight DACs, with specific splitter cases up to 3 m.
OPTICS / LONGERConnectorized optical pathUse the exact supported transceiver plus fiber when reach, routing, serviceability or future fiber reuse favor pluggable optics.
AOC / SPECIAL CASEOnly where NVIDIA documents itCurrent native 100G-PAM4 NDR is not a general AOC product family; special backward-compatible AOCs exist for selected 200G / HDR paths.
Topology Matters
The same distance can require different interconnects
Switch → adapter / DPU
- Identify the exact Quantum switch cage and target port.
- Identify ConnectX / DPU endpoint form factor.
- Confirm NDR 400G, NDR200 or breakout mode.
- Use the specific switch-to-adapter cable / transceiver topology documented by NVIDIA.
Switch → switch / breakout
- Twin-port OSFP switch cages can carry two 400G engines in NVIDIA's NDR ecosystem.
- 800G-to-two-400G and other splitter topologies are product-specific.
- Fiber type and both optical ports must match the documented implementation.
- Do not infer splitter support from connector appearance alone.
AOC Boundary
Why “AOC for NDR” needs an exact compatibility check
NVIDIA's current 100G-PAM4 documentation explicitly distinguishes native interconnects from backwards-compatible AOC cases.
Specific AOCs do exist
NVIDIA documents selected 2×200G-to-2×HDR AOC assemblies for backward compatibility to 50G-PAM4 HDR / 200GbE systems.
Never substitute by medium name alone
If a BOM says AOC, capture both endpoints and NVIDIA part evidence before replacing it with DAC or transceiver + fiber—or vice versa.
Official Evidence
Use NVIDIA LinkX documentation for the actual NDR path
400G 100G-PAM4 Interconnect Guide
Covers Quantum-2, Spectrum-4, ConnectX-7 / ConnectX-8, BlueField-3 and supported interconnect configurations.
DAC / LACC Overview
Use the current NVIDIA cable documentation for copper length classes, splitter limitations and product lifecycle.
400G Transceiver & Fiber Parts
Use current NVIDIA part lists for exact optical endpoints, fiber and supported topology.
Evidence boundary: QIANWU does not infer NDR compatibility from “400G”, “OSFP”, “AOC” or “DAC” labels alone. Final media selection is tied to the exact switch, adapter / DPU, port mode, NVIDIA-supported interconnect and project validation.
Need to structure an NDR interconnect BOM?
Send both endpoint models, port mode, link distance, topology, quantity and target deployment date.