QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT 400G QSFP-DD 8 x 50G PAM4 to 2 x 200G QSFP56 4 x 50G PAM4 Passive Copper Breakout Cable, 2.5m (8ft)
This page gives procurement and network teams a precise reference for Generic QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT: a 400G DAC assembly in a fixed 2.5m (8ft) configuration. The QSFP-DD to 2x QSFP56 interface, HT ordering identity and verified specifications are presented together so the required cable can be matched to the bill of materials without confusing it with another length.
OEM Part Number: QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FTHT Part Number: QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT
Product Highlights
- HT-manufactured DAC assembly in 2.5m (8ft)
- 400G connectivity at 400Gbps
- Interface configuration: QSFP-DD to 2x QSFP56
- Fixed length and part number: 2.5m (8ft), QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT
- Cable construction: Passive Twinax
- Conductor specification: 28AWG
- Maximum power consumption: 0.1W (QSFP-DD End) 0.1W (QSFP56 Per End)
- Minimum bend radius: 39.5mm
Specifications
| HT Part Number | QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT |
|---|---|
| Manufacturer | HT |
| Connector Type | QSFP-DD to 2x QSFP56 |
| Max. Data Rate | 400Gbps |
| Media | Copper |
| Cable Type | Passive Twinax |
| Cable Length | 2.5m (8ft) |
| Wire AWG | 28AWG |
| Minimum Bend Radius | 39.5mm |
| Max. Power Consumption | 0.1W (QSFP-DD End) 0.1W (QSFP56 Per End) |
| Jacket Material | PVC |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Protocols | IEEE802.3Bj, By, IEEE802.3CD, SFF-8679, SFF-8636 |
| Application | 400G Ethernet |
| Modulation Technology | PAM4 |
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.
Position Within the Length Range
QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT occupies the middle of this family between QSFP-DD to 2x QSFP56-400G-DAC-2M7FT at 2m (7ft) and QSFP-DD to 2x 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 39.5mm; the stated power consumption is 0.1W (QSFP-DD End) 0.1W (QSFP56 Per End); the jacket material is PVC.
Cable Construction and Routing
This assembly uses 28AWG conductors, PVC jacket, minimum bend radius 39.5mm. 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 IEEE802.3Bj, By, IEEE802.3CD, SFF-8679, SFF-8636. Confirm that the host firmware and port configuration support the same operating mode.
Breakout Port Mapping
The QSFP-DD to 2x 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 2x QSFP56-400G-DAC-2.5M8FT reaches both ports without tension at either connector.
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. Where supported by the host, link stability and diagnostic indications are reviewed together with the established link.
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. Keep QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT associated with 2.5m (8ft) throughout the order and receiving record.
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. Volume orders can include customer references on the labels and carton list.
Frequently Asked Questions
Is this an original equipment manufacturer cable?
No. It is manufactured by HT under our own manufacturer identity.
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.
Can excess cable be folded into a compact bundle?
No. Use a supported, bend-safe service loop and observe the listed minimum bend radius. Do not crease the cable or tighten ties around the connector boots.
Will any matching connector operate at the same speed?
Not necessarily. Both hosts must support the stated rate, identification, lane mapping and any required breakout configuration; mechanical compatibility alone is insufficient.
Shipping and Lead Time
Standard configurations normally ship within one to three working days, while production quantities are confirmed with the order. International express, air cargo and sea freight can be selected according to destination and carton volume; customer courier accounts and nominated forwarders are also accepted.