LinkX User Guide for 400G and 200G using 50G-PAM4 and 100G using 25G-NRZ Modulation Cables and Transceivers


You can download a PDF version of the full guide here.

NVIDIA LinkX QSFP-based Cables and Transceiver Portfolio

LinkX 400GbE Cables and Transceivers Portfolio

This document profiles 400Gb/s QSFP-DD-based cables and transceivers for Ethernet only from 0.5-meters to 10km

The LinkX® 400GbE QSFP-DD portfolio consists of straight and splitter DACs, an AOC cable and five transceivers with reaches from 1-to 10k-meters. QSFP-DD cables and transceivers support only Ethernet.

NVIDIA 400GbE QSFP-DD product line:

  • DAC cables have 1:2 and 1:4 split configuration with maximum reach of 2.5-meters
  • AOC have only QSFP-DD-to-QSFP-DD AOC and no splitters.
  • 400GbE SR8 multimode transceiver can be split to 2x 200G QSFP56 and to 2x 100G

    • Use 3rd party MPO-16/APC-to-2x MPO-12/UPC fiber cables – not offered by NVIDIA.
    • Note, the 400GbE SR8 uses a 16-fiber MPO-16/APC optical connector
  • 400GbE DR4 can be split to 4x 100G DR1 using 3rd party supplied splitter fiber cables.

    • MPO-12/APC-to-4x LC Duplex
    • DR1 is 1x100G-PAM4 optical to 4x25G-NRZ
  • 400G FR4 and LR4 are optically multiplexed and cannot be split and used for long, leaf-spin and spine-super spine links.

LinkX 400GbE Ethernet QSFP-DD Cables and Transceiver Portfolio


LinkX 200GbE and InfiniBand HDR Cables and Transceiver Portfolio

The LinkX 200GbE and InfiniBand HDR QSFP56 portfolio consists of straight and 1:2 splitter DACs and AOC cables, two transceivers with reaches from 1-to 2k-meters. Some of the parts are either InfiniBand or Ethernet specific with different part numbers, or sometimes a single part number supports both InfiniBand and Ethernet.

  • 200GbE and HDR portfolios are very similar, except the InfiniBand DACs are maximum reach of 2-meters.
  • 200G straight DAC and 200G SR4 multimode transceivers are InfiniBand part number specific and require more stringent BER testing.
  • InfiniBand cables and transceivers can be used in NVIDA Spectrum™ Ethernet switches in NVIDIA end-to-end configurations.InfiniBand testing is more stringent than Ethernet. However, Ethernet cables and transceivers cannot be used in InfiniBand systems.
  • 200GbE and HDR SR4 transceivers can be split into 2x 100G creating 2x50G-PAM4 QSFP56 100GbE or HDR100 ends.

    • Use 3rd party MPO-12/UPC-to-MPO-12/UPC fiber cables –- not offered by NVIDIA.
  • 200G FR4 is optically multiplexed and cannot be split and used for long, leaf-spin and spine-super spine links.
  • 200G FR4 can be used in ConnectX®-6 adapters under specific air flow conditions in servers; check the NVIDIA ConnectX-6 User Manual.
  • 200GbE and HDR use 4x50G PAM4 = 200G.
  • HDR100 and 100GbE based on 2x50G PAM4 is 100G and not compatible with 100GbE based on 4x25G-NRZ.

LinkX 200GbE Ethernet & HDR InfiniBand QSFP56 Cables and Transceiver Portfolio


NVIDIA Spectrum 400G, 200G, 100GbE Ethernet Switch Portfolio

There are many different switch port configurations in the Spectrum Ethernet switch product line using various combination of QSFP-DD, QSFP56, QSFP28 and SFP28. The DACs, AOCs and multimode transceiver are generally used in switch-to server links and multimode for longer links beyond 2.5-meter DAC maximum reach.

The NVIDIA Spectrum, Spectrum-2, Spectrum-3, and Spectrum-4 are successive switch IC generations dating back to 2015 with the Spectrum-4 being the latest offering. The Spectrum-4 is also offered as the SN5600 in twin-port OSFP 800G 64-port configuration based on 100G-PAM4 modulation.The Spectrum Ethernet switches are protocol specific and do not support InfiniBand.

NVIDIA Spectrum Ethernet Switch Portfolio

SN2000 SeriesSpectrum

QSFP28 & SFP28

SN3000 SeriesSpectrum-2

QSFP56, QSFP28 & SFP28

SN4000 SeriesSpectrum-3


SN5000 SeriesSpectrum-4






The 400GbE QSFP-DD cables and transceivers line is for the NVIDIA SN5400, SN4700, SN4410 Ethernet switches only and not used for InfiniBand. The QSFP-DD cages are backwards compatible and accept all QSFP-based cables and transceivers, both 50G-PAM4 and 25G-NRZ line rates and 25, 40, 100, 200, and 400G aggregate data rates. Similarly, the 200GbE QSFP56 cages are backwards compatible to QSFP28.

  • 400GbE
  • 200GbE
  • 100GbE



NVIDIA Quantum HDR 200G InfiniBand Switch Portfolio

The 200G HDR is offered in 32-ports of 200G HDR in QSFP56 cages.

  • QSFP56 cages accept 100G EDR cables and transceivers
  • HDR was the first InfiniBand products to offer 1:2 splitter DACs and AOCs

The HDR cables and transceivers product line overlaps the 200GbE Ethernet portfolio with a few InfiniBand-only exceptions for a DAC and SR4 transceiver. InfiniBand has a much lower bit error ratio (BER) requirement to minimize the use of forward error correction which induces significant latency.

NVIDIA Quantum HDR InfiniBand Switch Portfolio NVIDIA Quantum QM8700 Switch
32 cages QSFP56 200Gb/s


NVIDIA ConnectX Network Adapter Portfolio

The ConnectX line coverts PCIe bus signals to Ethernet or InfiniBand protocols. The ConnectX portfolio consists of three generation of adapter ICs.

  • 400GbE/NDR
  • 200GbE/HDR
  • 100GbE/EDR




  • ConnectX-7 is offered in 4x100G-PAM4 OSFP and QSFP112.
  • ConnectX-7 and most ConnectX-6 products support both Ethernet and InfiniBand.
  • SFP56 and OCP cards are Ethernet specific.
  • As with the switch port cages, the ConnectX-7 QSFP112 is backwards compatible to the slower QSFP56, QSFP28, etc. Similarly, for the QSFP56 based ConnectX-6 and QSFP28.
  • ConnectX line is not offered with QSFP-DD cages.

NVIDIA ConnectX-7 Network Adapter Portfolio


NVIDIA BlueField-3 DPU Portfolio

BlueField DPUs contain an ARM® CPU, memory, accelerators, PCIe switch and ConnectX-6 or ConnectX-7 adapters.

  • BlueField-2 DPUs are offered in 200G QSFP56 for InfiniBand and Ethernet
  • BlueField-3 DPUs are offered in 200G and 400G QSFP112 for InfiniBand and Ethernet
  • Not offered with OSFP or QSFP-DDs
  • QSFP112 cages accept 200G QSFP56 and 100G QSFP28

NVIDIA BlueField-3 DPU Portfolio 200G & 400G, InfiniBand and Ethernet QSFP112

Single QSFP112

Dual QSFP112



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