Cisco QDD-4ZQ100-CU0.5M Compatible 400G QSFP-DD 8 x 50G PAM4 to 4 x 100G QSFP56 2 x 50G PAM4 Passive Copper Breakout Cable, 0.5m (2ft)
For a direct equipment connection requiring Cisco QDD-4ZQ100-CU0.5M, this page supplies the 0.5m (2ft) version with QSFP-DD to 4x QSFP56. The cable supports 400G operation and eliminates a separate module-and-patch-cord assembly. Installation, maintenance and spare-cable identification are addressed alongside the full technical details.
OEM Part Number: QDD-4ZQ100-CU0.5MHT Part Number: QDD-4ZQ100-CU0.5M
Product Highlights
- Compatible alternative to Cisco QDD-4ZQ100-CU0.5M
- 400G connectivity at 400Gbps
- Interface configuration: QSFP-DD to 4x QSFP56
- Fixed length and part number: 0.5m (2ft), QDD-4ZQ100-CU0.5M
- Conductor specification: 30AWG
- Maximum power consumption: 0.1W (QSFP-DD End)0.1W (QSFP56 Per End)
- Minimum bend radius: 35mm
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| HT Part Number | QDD-4ZQ100-CU0.5M |
|---|---|
| Cisco Compatible | QDD-4ZQ100-CU0.5M |
| Manufacturer | HT |
| Form Factor | QSFP-DD to 4x QSFP56 |
| Max. Data Rate | 400Gbps |
| Minimum Bend Radius | 35mm |
| Wire AWG | 30AWG |
| Cable Length | 0.5m (2ft) |
| 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.
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 30AWG conductors, PVC jacket, minimum bend radius 35mm. 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.
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 0.5m (2ft) length is suited to closely aligned ports where excessive slack would obstruct airflow or complicate dressing. Measure the actual port-to-port path before choosing QDD-4ZQ100-CU0.5M; even a short assembly must retain the specified bend radius and should never be pulled tight behind the equipment.
Position Within the Length Range
QDD-4ZQ100-CU0.5M is the shortest of 6 verified length options in this family. It is the preferred choice when the port positions are close and cable slack must be kept to a minimum. The next option is QDD-4ZQ100-CU1M at 1m (3ft), adding 0.5m for a less direct routing path; selecting it unnecessarily would leave more cable to dress.
Field Installation and Maintenance
Inspect the route and both connectors before installation, then support the cable without pulling on either connector housing. During maintenance, release the latch properly rather than using the cable as a handle. Keep protection on unused ends, and if the assembly is removed for later use, coil it loosely and record its part number so the same length can be returned to service. For this assembly, the listed conductor specification is 30AWG; the minimum bend radius is 35mm; the stated power consumption is 0.1W (QSFP-DD End)0.1W (QSFP56 Per End); the jacket material is PVC.
Quality Assurance and Packaging
The cable and both connectors are inspected before a functional link test. Connector protection and bend-safe packing reduce handling damage during transport and storage. Customer or site labels can be added for field inventories, with different lengths separated to simplify issue and return of spare assemblies. Volume orders can include customer references on the labels and carton list.
Cisco Compatibility and Factory Testing
A field-ready cable needs both correct identification and a stable operating link. Our pre-packing check therefore includes the connectors, host recognition and link behavior. For equipment with uncertain revision history, providing the host model and software release helps identify compatibility requirements before the assembly reaches the installation site. Both connectors are examined before the operating test, which includes link stability and diagnostic indications.
Frequently Asked Questions
Is this an original Cisco cable?
No. It is an HT-manufactured compatible alternative for equipment that specifies Cisco QDD-4ZQ100-CU0.5M.
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.
Ordering Information
Request the cable by its exact part number and length, and state the equipment model if compatibility confirmation is needed. Site orders can list quantities by rack or installation team. Any requested label should retain the part number so a removed or spare cable can still be identified accurately. Keep QDD-4ZQ100-CU0.5M associated with 0.5m (2ft) throughout the order and receiving record.
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.
