Cisco QDD-400-CU0.5M Compatible 400G QSFP-DD 8 x 50G PAM4 Passive Copper Twinax Cable, 0.5m (2ft)

For short, high-density connections, this DAC cable combines 400G performance with a fixed 0.5m (2ft) cable run. It corresponds to Cisco QDD-400-CU0.5M and uses a factory-terminated passive copper link without separate optical modules or patch cords.

OEM Part Number: QDD-400-CU0.5MHT Part Number: QDD-400-CU0.5M

Product Highlights

• Compatible alternative to Cisco QDD-400-CU0.5M
• 400G connectivity at 400Gbps
• Interface configuration: QSFP-DD to QSFP-DD
• Fixed length and part number: 0.5m (2ft), QDD-400-CU0.5M
• Cable construction: Passive Twinax
• Conductor specification: 30AWG
• Maximum power consumption: 0.1W Per End
• Minimum bend radius: 33mm

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.

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.

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-400-CU0.5M; even a short assembly must retain the specified bend radius and should never be pulled tight behind the equipment.

QDD-400-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-400-CU1M at 1m (3ft), adding 0.5m for a less direct routing path; selecting it unnecessarily would leave more cable to dress.

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.

This assembly uses 30AWG conductors, PET jacket, minimum bend radius 33mm. 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.

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.

Compatibility is more than matching the QSFP-DD to QSFP-DD shape. This assembly is prepared for hosts expecting QDD-400-CU0.5M and is checked for identification, stable link behavior and electrical continuity, link stability and diagnostic readouts. We recommend confirming the equipment model and software release for critical deployments or mixed-vendor installations.

Quote HT part number QDD-400-CU0.5M with the required quantity. The 0.5m (2ft) length is fixed for this part number; if a different length is needed, select its corresponding page and OEM reference from the length list above. Standard HT labels and project-specific packaging are available.

HT inspects and tests every completed cable before it enters finished stock. Protective caps or covers are fitted where applicable, followed by anti-static or tray packaging and an outer carton. Custom labels can cross-reference the customer part number, QDD-400-CU0.5M and the 0.5m (2ft) length for easier inventory control.

Available stock is usually packed and handed to the carrier within one to three working days. Delivery can be arranged by international express, air cargo or sea freight, with tracking details supplied after dispatch. Freight-collect shipments and delivery to a customer warehouse or forwarder can also be coordinated.