QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FTQSFP-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)
For densely populated equipment, the fixed 2.5m (8ft) version of Generic QSFP-DD to 2x QSFP56-400G-DAC-2.5M8FT offers a clearly defined 400G link without separate optical modules or patch cords. The DAC assembly uses QSFP-DD to 2x QSFP56; its power, mechanical and diagnostic details are listed where supplied so port density and cable management can be assessed together.
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.
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.
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.
High-Density Rack Integration
In a densely populated rack, connector access and airflow are part of the link design. Choose the shortest length that follows the managed path comfortably, avoid tight bundles around the connector housings and preserve room for latch operation. Where power consumption is listed, include every populated interface in the host thermal budget rather than assessing a single cable in isolation. 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.
Quality Assurance and Packaging
Each assembly receives a visual connector inspection and functional link check before it is coiled and protected. Packaging is selected to avoid compressing the cable into a tight bundle, and optional rack-based labels help maintain an orderly installation when many identical interfaces are populated together. Volume orders can include customer references on the labels and carton list.
Ordering Information
Provide the exact part number, length, quantity and target interface density. For multi-rack projects, list each length separately and identify any preferred carton grouping. Host model and software information can be included for a compatibility review before production or dispatch. This page’s fixed configuration is 2.5m (8ft); another length must be quoted under its corresponding part number.
Generic Compatibility and Factory Testing
The assembly is evaluated for host recognition and stable link operation, with diagnostics checked where the interface provides them. This approach verifies more than electrical or optical continuity. Exact platform and firmware information remains valuable in high-density deployments because port mode and qualification policy can differ within the same connector family. Both connectors are examined before the operating test, which includes link stability and diagnostic indications.
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, with production quantities confirmed at order stage. Worldwide courier services are available, with air or sea freight for consolidated shipments; freight-collect delivery and coordination with a customer’s logistics provider can be arranged.
