Dell QDD-SR4-400G Compatible 400G QSFP-DD SR4 Transceiver Module
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 MPO-12/APC as the physical interface. The specifications and engineering guidance below support project teams keep OEM references, delivery records and port schedules aligned, while keeping HT manufacture separate from the OEM cross-reference.
OEM Part Number: QDD-SR4-400GHT Part Number: QDD-SR4-400G
Product Highlights
- Compatible alternative to Dell QDD-SR4-400G
- 400G connectivity at 400Gbps
- Optical wavelength: 850nm
- Specified reach: 30m on OM3 / 50m on OM4
- MPO-12/APC / MMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| 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 | MPO-12/APC |
| Media | MMF |
| Transmitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -4.6~4dBm |
| Minimum Receiver Power | -6.4dBm |
| Power Budget | 1.8dB |
| Receiver Overload | 4dBm |
| Max. Power Consumption | 8W |
| Extinction Ratio | 2.5dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation (Electrical) | 8x50G-PAM4 |
| Modulation (Optical) | 4x100G-PAM4 |
| 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 |
Project Documentation and Traceability
Large deployments are easier to audit when the order code, optical standard and endpoint record agree. Keep the OEM reference in the compatibility document and the HT part number on the packing list. Labels and carton groups can be arranged by rack or port plan so installers need not identify modules by appearance. For this model, the principal parameters are data rate 400Gbps, wavelength 850nm, rated reach 30m on OM3 / 50m on OM4.
Dell Compatibility and Factory Testing
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.
Applications and Optical Link Design
Typical deployments include switch-to-switch, switch-to-server and aggregation links inside a data hall or between adjacent equipment rooms. The 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 MPO-12/APC end faces clean and avoid tight bends. Different multimode standards are not interchangeable merely because they share a connector.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -4.6~4dBm; the stated optical power budget is 1.8dB. A sound acceptance record includes link state, diagnostic temperature, supply voltage and transmit or receive levels where the host exposes them. Compare the readings with the stated ranges rather than treating any received light as proof of adequate margin. Persistent alarms or borderline values should trigger an end-face and complete-channel inspection. 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.
Frequently Asked Questions
Is this an original Dell transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-SR4-400G, not an original Dell-branded module.
Which fiber and connector are required?
Use MPO-12/APC with MMF. The specified maximum reach is 30m on OM3 / 50m on OM4, subject to fiber quality and total link loss.
Can it be mixed with another wavelength or reach version?
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.
Ordering Information
Quote HT part number QDD-SR4-400G together with OEM reference QDD-SR4-400G and quantity. Add the host model and software release when pre-order verification is required. Neutral labels, customer packaging and project-specific compatibility review are available on request.
Shipping and Lead Time
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.
Quality Assurance and Packaging
Quality control covers the optical or electrical interface, host identification and operating link. The verified unit is then individually protected and cartoned. Customer references, rack groups and project packing lists can be added for volume orders.
