NVIDIA's 800G platform lineup spans four distinct product categories — each with different OSFP cage types, form factors, and transceiver requirements. Ordering the wrong module for any tier means a physical incompatibility, not a software fix.
Ordering the wrong 800G transceiver for your NVIDIA hardware is an expensive mistake. NVIDIA's current platform lineup uses different OSFP cage types, different form factors, and different protocols across switches, NICs, and DPUs. This guide maps every current NVIDIA platform to its compatible 800G transceiver types, explains the critical IHS versus RHS cage distinction, and provides a compatibility matrix you can reference when specifying modules for your deployment.
Table of Contents
12 comprehensive sections — jump to any topic- 1Why Compatibility Errors Are Costly
- 2Spectrum-4 Ethernet Switches
- 3Quantum-X800 InfiniBand Switches
- 4ConnectX-8 SuperNIC
- 5IHS vs RHS: The Physical Difference
- 6BlueField-3 DPU
- 7DGX SuperPOD Cabling Requirements
- 8Full Compatibility Matrix
- 9Spectrum-4 Module Details
- 10QM3400 Module Details
- 11Vitex NVIDIA-Compatible Portfolio
- 12Getting Expert Support
1. Why Compatibility Errors Are Costly
Ordering the wrong 800G transceiver for your NVIDIA hardware is an expensive mistake. NVIDIA's current platform lineup uses different OSFP cage types, different form factors, and different protocols across switches, NICs, and DPUs. A twin-port IHS module that works perfectly in a Quantum-X800 switch will not physically fit in a ConnectX-8 SuperNIC. A QSFP112 module designed for BlueField-3 has nothing to do with the OSFP slots on a Spectrum-4.
IHS and RHS OSFP — broadest compatibility
IHS OSFP only — twin-port modules exclusively
RHS OSFP only — single-port modules only
QSFP112 only — entirely separate form factor
2. Spectrum-4 Ethernet Switches (SN5600)
The Spectrum-4 platform is NVIDIA's flagship 800G Ethernet switch, delivering 51.2 Tbps aggregate switching capacity across 64 OSFP ports. It is the most versatile platform in the NVIDIA lineup for 800G transceiver compatibility because it supports both IHS (Integrated Heat Sink) and RHS (Riding Heat Sink) OSFP modules.
This flexibility means Spectrum-4 can accept twin-port modules like the 800G 2xDR4 (which requires IHS cages for thermal dissipation) as well as single-port modules like the 800G SR8 or DR4 in RHS form factor. It also supports full breakout capability: each 800G port can be split into 2x400G, 4x200G, or 8x100G using the appropriate breakout cables and transceiver configurations. For AI clusters running Ethernet-based GPU fabrics (RoCEv2), the Spectrum-4 is the standard choice with the broadest module compatibility.
3. Quantum-X800 InfiniBand Switches (QM3400)
The Quantum-X800 (QM3400) is NVIDIA's top-tier InfiniBand switch, delivering 115.2 Tb/s aggregate bandwidth using 72 twin-port OSFP cages with four Quantum-3 ASICs. This platform uses exclusively IHS OSFP cages designed for the higher thermal load of twin-port transceivers.
Compatible XDR transceivers include the MMS4A00-XM (twin-port 2xDR4, 1.6T aggregate per module, IHS form factor). Each twin-port module provides two independent 800G InfiniBand XDR links from a single OSFP cage — this is how the QM3400 achieves 144 effective 800G ports from 72 physical cages. The key constraint: RHS (flat-top) modules will not work in the QM3400's IHS cages. Always specify IHS form factor when ordering for this platform.
4. ConnectX-8 SuperNIC (C8180)
The ConnectX-8 SuperNIC supports 800Gb/s InfiniBand XDR or 2x400GbE Ethernet through a single OSFP port. However, the NIC's OSFP cage is RHS (flat-top) only. The single-port cage design cannot accommodate twin-port IHS modules due to height constraints.
Compatible modules include the MMS4A20-XM800 (single-port DR4, 800G, 500m over single-mode fiber) and other RHS-compatible OSFP modules. This is a critical distinction for procurement: if you are deploying ConnectX-8 alongside Quantum-X800 switches, the switches use IHS modules and the NICs use RHS modules. They are not interchangeable.
ConnectX-8 Compatible
- 800G SR8 — OSFP RHS
- 800G DR4 (single-port) — OSFP RHS
- MMS4A20-XM800 — single-port DR4, 800G, 500m
- Any single-port RHS OSFP module
ConnectX-8 Incompatible
- 800G DR8 — OSFP IHS (will not fit)
- 800G 2xDR4 — OSFP IHS twin-port (will not fit)
- 800G 2xFR4 — OSFP IHS twin-port (will not fit)
- QSFP112 modules (wrong form factor entirely)
5. IHS vs RHS: The Physical Difference
IHS (Integrated Heat Sink): The heatsink is built into the transceiver module itself, creating a taller profile. The module's top surface has fins or a heat spreader. Requires a taller OSFP cage. Used in switches where cage height is not constrained.
RHS (Riding Heat Sink): The module has a flat top. A heatsink attached to the cage lid presses down onto the module from above. Used in space-constrained designs like NICs where the OSFP cage height is limited by the PCIe card form factor. Only single-port modules are available in RHS.
OSFP IHS vs RHS cage type comparison for NVIDIA 800G platforms — switches (Spectrum-4, QM3400) use the taller IHS cage; NICs (ConnectX-8) use the space-constrained RHS cage. The two are physically incompatible.
IHS — Integrated Heat Sink
- Heatsink built into the transceiver module itself
- Taller profile — fins or heat spreader on top surface
- Requires a taller OSFP cage
- Used in switches where cage height is not constrained
- Twin-port and single-port modules available in IHS
RHS — Riding Heat Sink
- Module has a flat top surface
- Heatsink is part of the cage lid, pressing down onto the module
- Used in space-constrained designs like PCIe NICs
- Only single-port modules available in RHS form factor
- Cannot accommodate twin-port modules due to height constraints
6. BlueField-3 DPU
BlueField-3 DPUs use QSFP112 form factor exclusively — not OSFP. This maintains compatibility with the existing 400G NDR InfiniBand ecosystem while supporting the DPU's integrated processing architecture. The QSFP112 cages accept 400G NDR InfiniBand transceivers with flat-top (RHS-style) thermal design.
If your deployment includes BlueField-3 DPUs alongside 800G switches and NICs, you will need a separate category of transceivers for the DPU tier. Do not attempt to source OSFP modules for BlueField-3 — they are physically incompatible.
7. DGX SuperPOD Cabling Requirements
A DGX SuperPOD deployment spans multiple NVIDIA platforms simultaneously: GPU nodes with ConnectX-8 NICs, leaf and spine switches (Spectrum-4 or Quantum-X800), and potentially BlueField-3 DPUs for storage or infrastructure management. Each tier has its own transceiver requirements, creating a multi-form-factor procurement challenge.
The GPU-to-leaf connections (ConnectX-8 to Spectrum-4) use RHS OSFP modules. The leaf-to-spine connections may use either IHS or RHS depending on configuration. The storage/infrastructure tier (BlueField-3) uses QSFP112 modules. Planning the full transceiver bill of materials requires mapping each tier explicitly.
← swipe to scroll →| SuperPOD Tier | Platform Connection | Required Form Factor | Module Type |
|---|---|---|---|
| GPU-to-leaf | ConnectX-8 to Spectrum-4 | OSFP RHS (both ends) | 800G SR8 or DR4 single-port |
| Leaf-to-spine (Ethernet) | Spectrum-4 to Spectrum-4 | OSFP IHS or RHS | 800G DR8, 2xDR4, or SR8 |
| Leaf-to-spine (InfiniBand) | Spectrum-4 to Quantum-X800 | IHS on QM3400 end | IHS module at switch; verify Spectrum-4 end |
| Storage / infrastructure | BlueField-3 DPU | QSFP112 (separate) | 400G NDR InfiniBand QSFP112 |
8. Full Compatibility Matrix
NVIDIA 800G module compatibility matrix — OSFP IHS modules work in switches only, RHS modules work in switches and NICs, and QSFP112 is exclusive to BlueField-3 DPUs. Use this chart before placing any transceiver order.
| Module | Form Factor | Spectrum-4 | QM3400 | ConnectX-8 | BlueField-3 | Reach |
|---|---|---|---|---|---|---|
| 800G DR8 | OSFP IHS | Yes | Yes | No | No | 500m |
| 800G 2xDR4 | OSFP IHS | Yes | Yes | No | No | 500m |
| 800G 2xFR4 | OSFP IHS | Yes | Yes | No | No | 2km |
| 800G SR8 | OSFP RHS | Yes | No | Yes | No | 100m |
| 800G DR4 (single) | OSFP RHS | Yes | No | No | No | 500m |
| 400G NDR | QSFP112 | No | No | No | Yes | 500m |
9. Spectrum-4 Module Details
The Spectrum-4 supports both IHS and RHS OSFP modules, making it the only NVIDIA platform with full flexibility across the entire 800G transceiver catalog. IHS modules — including twin-port 2xDR4 and 2xFR4 — are accepted in the Spectrum-4's taller cages alongside single-port RHS modules. This dual-cage-type support is a deliberate design choice that allows Spectrum-4 to serve as the interconnect hub between ConnectX-8 NICs (which require RHS modules) and Quantum-X800 switches (which require IHS modules) within the same SuperPOD fabric.
For breakout deployments, the Spectrum-4 supports all four breakout modes: 1x800G native, 2x400G, 4x200G, and 8x100G. Each breakout mode is controlled by the breakout cable and transceiver selection — the switch itself does not require separate configuration for the breakout ratio beyond the standard port-mode setting in Cumulus Linux or NVIDIA OS.
10. QM3400 Module Details
The Quantum-X800 (QM3400) achieves its 144 effective 800G port count through twin-port IHS modules that deliver two independent 800G InfiniBand XDR links from a single physical OSFP cage. The MMS4A00-XM is the primary compatible transceiver: a twin-port 2xDR4 module in IHS form factor, providing 1.6T aggregate bandwidth per module over two independent MPO-12 fiber paths to two separate 800G endpoints.
The IHS-only cage design of the QM3400 is a thermal necessity. Twin-port modules dissipate significantly more heat than single-port modules — the integrated heatsink on IHS modules provides the thermal headroom required for reliable operation at 800G per port. Attempting to use RHS modules in the QM3400 is not a configuration error that can be worked around; it is a physical incompatibility.
MMS4A00-XM Module Specs
- Form factor: OSFP IHS (twin-port)
- Protocol: 800G InfiniBand XDR (2x links)
- Aggregate per module: 1.6T
- Connector: 2x MPO-12 (one per optical engine)
- Max reach: 500m over OS2 single-mode fiber
QM3400 Port Math
- Physical OSFP cages: 72
- Twin-port modules per cage: 1
- Effective 800G InfiniBand ports: 144
- Aggregate switch bandwidth: 115.2 Tb/s
- ASICs: 4x Quantum-3
11. Vitex NVIDIA-Compatible Portfolio
Vitex stocks 800G OSFP modules in both IHS and RHS form factors compatible with the full NVIDIA platform lineup. For guidance on which interconnect type pairs with each platform, see our Interconnect Selection Guide.
← swipe to scroll →| Module | Form Factor | Reach | Compatible Platforms | Delivery |
|---|---|---|---|---|
| 800G DR8 | OSFP IHS | 500m OS2 | Spectrum-4, QM3400 | 4–7 weeks |
| 800G 2xDR4 | OSFP IHS | 500m OS2 | Spectrum-4, QM3400 | 4–7 weeks |
| 800G 2xFR4 | OSFP IHS | 2km OS2 | Spectrum-4, QM3400 | 4–7 weeks |
| 800G SR8 | OSFP RHS | 100m OM4/OM5 | Spectrum-4, ConnectX-8 | 4–7 weeks |
| 800G DR4 (single) | OSFP RHS | 500m OS2 | Spectrum-4, ConnectX-8 | 4–7 weeks |
Quick-reference summary for NVIDIA 800G transceiver form factor selection across Spectrum-4, QM3400, ConnectX-8, and BlueField-3 — use before placing any module order for a NVIDIA AI cluster deployment.
12. Getting Expert Support
Vitex has been a trusted fiber optics partner for over 23 years, serving data center operators, telecom carriers, and enterprise networks worldwide. With US-based engineering support and shorter lead times than major OEMs, we help teams move from design to deployment faster. Contact our engineering team for platform-specific module recommendations and compatibility verification.
