Direct Attach DAC Cable CBO QSFP28-DAC-0.5M 0.5 m QSFP28 passive copper

CBO QSFP28-DAC-0.5M 0.5 m QSFP28 passive copper is a 0.5 metre Direct Attach copper cable with QSFP28 connectors engineered for short-range, high-speed interconnects. It provides a direct electrical connection for 100 Gigabit Ethernet links between switches, servers and network interface cards, delivering low latency and energy-efficient operation without the need for optical transceivers. The compact passive construction makes it suitable for dense data centre top-of-rack and aggregation deployments where reliable, cost-effective short-reach connectivity is required.

Advantages

The passive QSFP28 DAC offers predictable performance with low insertion loss and minimal signal processing, resulting in reduced latency compared with active or optical solutions. Its 0.5 m length minimises cable clutter in rack environments and helps maintain airflow and cooling efficiency. Because it does not require additional transceivers or power for signal conversion, the cable lowers total system power consumption and simplifies inventory by combining connector and cable in a single unit.

Suitable for

• 100 Gigabit Ethernet connections between top-of-rack switches and aggregation switches
• Server-to-switch and NIC-to-switch links in data centres
• Short-reach interconnects inside racks or between adjacent racks
• Environments prioritising low latency and reduced power draw

Key specifications

• Connector type: QSFP28 to QSFP28
• Length: 0.5 m (0.5 metre)
• Cable type: Passive copper direct attach
• Supported link speed: 100 Gb/s
• Typical use: Short-range, rack-level interconnects
• Operating environment: Data centre and networking racks

How to use

Insert each QSFP28 connector into the corresponding QSFP28 port on the two devices to be connected, ensuring the latch engages securely. Verify link status on connected devices and monitor for expected 100 Gb/s negotiation. No additional configuration or power source is required for the passive cable itself; treat it as a fixed copper link within the host devices' port settings and management interfaces. Handle the cable by the connector housings and avoid sharp bends at the termination points to maintain signal integrity.

Recommendations

For reliable operation, use this 0.5 m passive QSFP28 DAC for short-distance rack-level connections only. Avoid stretching beyond the specified length and keep bend radii gentle near connectors. Ensure compatibility with device QSFP28 port specifications and firmware recommendations before deployment, and maintain proper cable management to support airflow in dense rack installations.