QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT 400G QSFP-DD 8 x 50G PAM4 to 4 x 100G QSFP56 2 x 50G PAM4 Passive Copper Breakout Cable, 2.5m (8ft)

For buyers working from an equipment parts list, QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT identifies more than a connector style. It refers here to a 2.5m (8ft) DAC cable for Generic hosts, supporting 400G operation with QSFP-DD to 4x QSFP56. The sections below separate the OEM cross-reference, physical specification and HT factory checks for straightforward purchasing review.
OEM Part Number: QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FTHT Part Number: QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT
Product Highlights
- HT-manufactured DAC assembly in 2.5m (8ft)
- 400G connectivity at 400Gbps
- Interface configuration: QSFP-DD to 4x QSFP56
- Fixed length and part number: 2.5m (8ft), QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT
- Conductor specification: 28AWG
- Maximum power consumption: 0.1W (QSFP-DD End)0.1W (QSFP56 Per End)
- Minimum bend radius: 41mm
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| HT Part Number | QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT |
|---|---|
| Manufacturer | HT |
| Form Factor | QSFP-DD to 4x QSFP56 |
| Max. Data Rate | 400Gbps |
| Minimum Bend Radius | 41mm |
| Wire AWG | 28AWG |
| Cable Length | 2.5m (8ft) |
| Jacket Material | PVC |
| Media | Copper |
| Modulation Format | QSFP-DD-8x 50G-PAM4QSFP56-2x 50G-PAM4 |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Power Supply | 3.3V |
| Protocols | SFF-8665, QSFP-DD MSA, IEEE802.3bj, IEEE802.3 cd |
| Max. Power Consumption | 0.1W (QSFP-DD End)0.1W (QSFP56 Per End) |
| Application | 400G Ethernet |
Signal and Lane Configuration
The listed modulation format is QSFP-DD-8x 50G-PAM4QSFP56-2x 50G-PAM4. Both host interfaces must be configured for the same aggregate rate and lane arrangement. A connector that fits mechanically does not by itself guarantee that the remote port supports this encoding or breakout mode.
Breakout Port Mapping
The QSFP-DD to 4x QSFP56 configuration divides the high-speed interface into multiple lower-speed connections. Verify the upstream lane assignment, downstream port speeds and breakout setting on the host before connecting the assembly. Each branch must attach to the correct remote interface.
Passive Copper Operation
A passive DAC has no separate optical conversion stage. Its low-power, low-latency operation is useful for short equipment links, but the assembly must remain within the length and signaling mode accepted by both hosts.
Length Selection and Installation Planning
The 2.5m (8ft) version is useful when a two-metre run would leave insufficient working slack. Before installation, check the complete horizontal and vertical path so that QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT reaches both ports without tension at either connector.
Position Within the Length Range
QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT occupies the middle of this family between QSFP-DD to 4x QSFP56-400G-DAC-2M7FT at 2m (7ft) and QSFP-DD to 4x QSFP56-400G-DAC-3M10FT at 3m (10ft). It adds 0.5m over the shorter option for extra routing clearance, while the next longer version adds another 0.5m. Measure the managed path and choose this version when its reach is sufficient without creating the slack associated with the longer assembly.
Procurement and Port-Mapping Review
A useful purchase order should identify the host platform, the expected OEM code and the exact cable length as separate pieces of information. This prevents a physically similar assembly from being substituted when the port identification or reach is different. For mixed-length installations, prepare one order line per part number and reconcile each delivered cable with its intended pair of ports. For this assembly, the listed conductor specification is 28AWG; the minimum bend radius is 41mm; the stated power consumption is 0.1W (QSFP-DD End)0.1W (QSFP56 Per End); the jacket material is PVC.
Power and Thermal Planning
The rated power consumption is 0.1W (QSFP-DD End)0.1W (QSFP56 Per End). Include this load in the host-port power and thermal budget, especially in densely populated switches. Maintain front-panel clearance and do not bundle the cable so tightly that it obstructs airflow around the connectors.
Cable Construction and Routing
This assembly uses 28AWG conductors, PVC jacket, minimum bend radius 41mm. These mechanical characteristics affect how the cable should be dressed behind the equipment. Avoid sharp edges, excessive ties and repeated tight bends close to the connector boots.
Network and Protocol Considerations
The intended application is 400G Ethernet. Listed interface and protocol references include SFF-8665, QSFP-DD MSA, IEEE802.3bj, IEEE802.3 cd. Confirm that the host firmware and port configuration support the same operating mode.
Generic Compatibility and Factory Testing
Our procurement-oriented compatibility check begins with the OEM reference and ends with a live host link. We record the physical length separately from the identification configuration, so the cable supplied for this page remains the stated version rather than a generic length substitute. The check includes link stability and diagnostic indications, followed by a final inspection of both ends.
Ordering Information
For a clear bill of materials, quote the OEM reference, HT part number, length and quantity on the same line. Add the switch or server model and software release when a pre-order review is required; project labels can repeat those details for receiving and installation teams. This page’s fixed configuration is 2.5m (8ft); another length must be quoted under its corresponding part number.
Quality Assurance and Packaging
Before packing, the assembly is checked for connector condition, identification and link operation. Cables for multi-line orders can be labelled and grouped by part number, making it easier to match each length to the procurement record without opening every protective bag. Neutral packaging and customer-specific packing documentation are available on request.
Frequently Asked Questions
Is this an original equipment manufacturer cable?
No. It is manufactured by HT under our own manufacturer identity.
Can different brands be connected with the same assembly?
Only where both hosts explicitly support the complete interface and compatibility arrangement. Document each end and select the appropriate brand-specific product when required.
Does this order code cover multiple lengths?
No. QSFP-DD to 4x QSFP56-400G-DAC-2.5M8FT refers here to 2.5m (8ft). Every other verified length has a separate part number and page in the length list.
Are separate transceivers or patch leads required?
No. This is one complete direct-attach assembly. The ends are not detachable modules and should not be separated from the cable.
Shipping and Lead Time
Available stock is generally dispatched within one to three working days after order confirmation, with production lead times advised for larger quantities. Delivery can be arranged by courier, air freight or sea freight, and goods may instead be handed to an appointed forwarder or shipped on the customer’s courier account.