NVIDIA/Mellanox Compatible 800GBASE-DR4 OSFP112 RHS/Flat Top 8x100G PAM4 Broadcom 3nm DSP 1310nm 500m SMF DOM MPO-12/APC Optical Transceiver Module for ConnectX-8 C8180 SuperNIC

O112-800G-DR4: Frequently Asked Questions

Q: Why choose the O112-800G-DR4 when upgrading to 1.6T networks?

A: The O112-800G-DR4 is designed to connect NVIDIA ConnectX-8 800G NICs to compatible 1.6T Ethernet switches, allowing existing 800G NIC infrastructure to be integrated into a next-generation switching architecture without necessarily replacing the NICs. This approach can simplify network upgrades and help optimize switch-port utilization, transceiver deployment, and fiber cabling. In a specific 288-server cluster design, the projected savings may reach up to 50% in switch count, 37.5% in optical transceiver quantity, and 50% in fiber cabling compared with a conventional 800G switch architecture. These figures are topology-dependent estimates rather than guaranteed results; actual savings depend on port allocation, oversubscription, redundancy, and network design.

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Q: Why are there two versions of 800G OSFP112 DR4 transceivers?

A: The O112-800G-DR4 and O112-800G-DR4T share the same core optical and electrical architecture but use different thermal and housing designs for different host applications. The O112-800G-DR4 features a Flat Top housing and is primarily intended for ConnectX-8 NIC applications, where the NIC cage and host cooling system provide the required thermal management. The O112-800G-DR4T uses a Closed Finned Top housing with integrated heat sink fins and is intended for compatible OSFP switch ports that require this module-level cooling design. Always select the housing version specified for the host device.

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Q: Which networking scenarios in NVIDIA B300 and GB300 NVL72 systems require the O112-800G-DR4 transceiver?

A: The O112-800G-DR4 is intended for the server/NIC side of compatible network architectures, connecting NVIDIA ConnectX-8 800G NICs to supported 1.6T Ethernet switches, including compatible TH6-based platforms and NVIDIA Spectrum-6 switches. It can be used in RoCE network designs for NVIDIA B300 and GB300 NVL72 AI infrastructure, subject to the system’s supported NIC, switch, port, and firmware configurations.

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Q: Which 800G transceiver should I choose for connecting NVIDIA ConnectX NICs to 1.6T switches?

A: The appropriate transceiver depends on the NIC model and the host-side electrical interface. The O112-800G-DR4 is designed for ConnectX-8 NIC-to-compatible 1.6T switch interconnections. The OSFP-800G-DR4 is intended for ConnectX-9 NIC-to-compatible 1.6T switch interconnections. The O112-800G-DR4 uses 8×100G PAM4 electrical lanes and 4×200G PAM4 optical lanes, with signal processing to support the electrical-to-optical lane-rate conversion. By comparison, the OSFP-800G-DR4 uses 4×200G PAM4 lanes on both the electrical and optical sides. Check the NIC’s optical interface requirements and the switch port specifications before selecting a module.

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Q: What are the benefits of using a 3nm DSP in an 800G transceiver?

A: A 3nm DSP process can help reduce chip power consumption and improve integration compared with earlier process generations, subject to the specific DSP design and implementation. In an 800G transceiver, the DSP supports high-speed signal processing and helps maintain signal integrity across demanding electrical and optical interfaces. NADDOD’s O112-800G-DR4 incorporates a Broadcom 3nm DSP and is specified for a maximum power consumption of ≤15W, making it suitable for power- and thermal-conscious AI data center deployments. Actual power and performance comparisons with 5nm solutions should be based on equivalent operating conditions and verified product test data.