Dell DAC-Q56DD-400G-2M Compatible 400G QSFP-DD 8 x 50G PAM4 Passive Copper Twinax Cable, 2m (7ft)
The DAC-Q56DD-400G-2M compatible assembly is intended for Dell equipment that requires a 400G direct-attached connection. This version is specifically 2m (7ft), with QSFP-DD to QSFP-DD and its own order reference. Exact length pages and equivalent brand references are linked to make multi-product procurement easier to verify.
OEM Part Number: DAC-Q56DD-400G-2MHT Part Number: DAC-Q56DD-400G-2M
Product Highlights
- Compatible alternative to Dell DAC-Q56DD-400G-2M
- 400G connectivity at 400Gbps
- Interface configuration: QSFP-DD to QSFP-DD
- Fixed length and part number: 2m (7ft), DAC-Q56DD-400G-2M
- Cable construction: Passive Twinax
- Conductor specification: 28AWG
- Maximum power consumption: 0.1W Per End
- Minimum bend radius: 39.5mm
Specifications
| HT Part Number | DAC-Q56DD-400G-2M |
|---|---|
| Dell(DE) Compatible | DAC-Q56DD-400G-2M |
| Manufacturer | HT |
| Form Factor | QSFP-DD to QSFP-DD |
| Max. Data Rate | 400Gbps |
| Media | Copper |
| Cable Type | Passive Twinax |
| Cable Length | 2m (7ft) |
| Wire AWG | 28AWG |
| Minimum Bend Radius | 39.5mm |
| Max. Power Consumption | 0.1W Per End |
| Jacket Material | PET (OFNR) |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation Format | 8x 50Gbps PAM4 |
| Application | 400G Ethernet |
| Protocols | IEEE 802.3cd, QSFP-DD MSA, CMIS 4.0 |
Signal and Lane Configuration
The listed modulation format is 8x 50Gbps 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.
Length Selection and Installation Planning
DAC-Q56DD-400G-2M provides 2m (7ft) for connections between separated rack units or nearby equipment positions. Plan the route around cable managers and power cords, keeping the assembly free from connector strain while avoiding a large obstruction in the airflow path.
Position Within the Length Range
DAC-Q56DD-400G-2M occupies the middle of this family between DAC-Q56DD-400G-1.5M at 1.5m (5ft) and DAC-Q56DD-400G-2.5M at 2.5m (8ft). 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 Per End; the jacket material is PET (OFNR).
Power and Thermal Planning
The rated power consumption is 0.1W 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, PET (OFNR) 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 IEEE 802.3cd, QSFP-DD MSA, CMIS 4.0. Confirm that the host firmware and port configuration support the same operating mode.
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.
Dell 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. This page’s fixed configuration is 2m (7ft); 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. Volume orders can include customer references on the labels and carton list.
Frequently Asked Questions
Is this an original Dell cable?
No. It is an HT-manufactured compatible alternative for equipment that specifies Dell DAC-Q56DD-400G-2M.
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. 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.