
Built for hosts recognizing QDD-SR4-400G, this HT-manufactured QSFP-DD module delivers 400G transmission at 850nm. Its rated reach is 30m on OM3 / 50m on OM4, with MTP/MPO-12 (APC) as the physical interface. The specifications and engineering guidance below support network teams verify host acceptance as well as physical interface fit, while keeping HT manufacture separate from the OEM cross-reference.
OEM Part Number: QDD-SR4-400GHT Part Number: QDD-SR4-400G
| HT Part Number | QDD-SR4-400G |
|---|---|
| Manufacturer | HT |
| Form Factor | QSFP-DD |
| Max. Data Rate | 400Gbps |
| Wavelength | 850nm |
| Max. Cable Distance | 30m@OM3/50m@OM4 |
| Connector | MTP/MPO-12 (APC) |
| Media | MMF |
| Transmitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -4.6~4dBm |
| RX Power | -6.3~4dBm |
| Modulation(Optical) | 4x100G-PAM4 |
| Modulation(Electrical) | 8x50G-PAM4 |
| Max. Power Consumption | 8W |
| Extinction Ratio | 2.5dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| DSP | TX and RX |
| Inbuilt FEC | Support |
| Core Size | 50/125µm |
| Packaging Technology | COB |
| MTBF | 1410258 Hours (@40°C, 90% CL) |
| Application | 400G Ethernet |
| Protocols | QSFP-DD MSA, CMIS Rev5.0, IEEE 802.3df-2024 |
| Power Budget | 1.8dB |
Typical deployments include switch-to-switch, switch-to-server and aggregation links inside a data hall or between adjacent equipment rooms. The MTP/MPO-12 (APC) interface connects to the specified multimode cabling, and the stated reach depends on fiber grade and link loss. Keep this interface on the matching multimode optical standard rather than connecting it directly to a single-mode wavelength or reach variant.
Before deployment, check the host port type, supported data rate and firmware requirements. The 400G interface configuration must match the remote equipment; sharing a QSFP-DD housing alone does not make two transceiver types interoperable.
The multimode channel should use the fiber grade associated with the stated 30m on OM3 / 50m on OM4 reach. Keep the MTP/MPO-12 (APC) end faces clean and avoid tight bends. Different multimode standards are not interchangeable merely because they share a connector.
Compatibility testing for QDD-SR4-400G combines identification with a live link and available transmit, receive and alarm information. Connector condition is inspected separately. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
For this model, the specified transmit-power range is -4.6~4dBm; the stated optical power budget is 1.8dB. During commissioning, record the host diagnostic readings after the link has stabilized and compare them with those limits. DOM values are useful operational indicators, but they do not replace calibrated optical measurements when a link is marginal. Investigate unexpected loss through connector inspection, cleaning and a channel measurement before replacing the module. Diagnostic monitoring is listed as Supported. Before every insertion, keep dust caps in place until the patch lead is ready, avoid touching the optical end face and use an appropriate inspection and cleaning procedure. Do not look into an active optical interface.
Check three layers before deployment: host acceptance of the module identity, port support for the stated rate, and a matching optical standard at the remote interface. For breakout operation, confirm lane configuration too. Similar-looking cages can behave differently across speeds and firmware settings. For this model, the principal parameters are data rate 400Gbps, wavelength 850nm, rated reach 30m on OM3 / 50m on OM4.
Use QDD-SR4-400G as the compatibility cross-reference and QDD-SR4-400G as the HT ordering identity. Keep other reaches or wavelength directions on separate order lines. Neutral labels, customer packaging and project-specific compatibility review are available on request.
Standard configurations normally ship within one to three working days, with production lead times confirmed for larger quantities. International courier, air freight and sea freight are available; customer courier accounts and nominated forwarders are accepted.
Before packing, the module receives interface inspection, identification and link checks. Protective packaging avoids pressure on the connector and latch. Customer references, rack groups and project packing lists can be added for volume orders.
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-SR4-400G, not an original NVIDIA/Mellanox-branded module.
Use MTP/MPO-12 (APC) with MMF. The specified maximum reach is 30m on OM3 / 50m on OM4, subject to fiber quality and total link loss.
Only when the two ends share the same optical standard, wavelength plan and supported data rate. Check the exact part numbers and link budget rather than relying only on the module form factor.