QSFP28 DAC Cable BlueOptics QSFP28-DAC-0.5M-SP-BL 0.5m Male/Male

The BlueOptics QSFP28 DAC Cable QSFP28-DAC-0.5M-SP-BL is a 0.5 m passive direct-attach twinax cable with male QSFP28 connectors on both ends. Designed for short-reach, high-speed interconnects, this cable supports 100GBase-CR4 electrical signalling and is suitable for linking equipment within racks or across adjacent racks in data centers and networking closets. The cable is offered as a tested, MSA-compliant solution for use with hardware platforms that accept QSFP28 direct-attach copper connections.

Advantages

This 0.5 m QSFP28 DAC provides low latency and low power consumption characteristic of passive twinax solutions, enabling efficient 100 Gbit/s links without active components. Built using MSA-compliant mechanical and electrical specifications, it offers predictable performance and interoperability with major switch, router and storage vendors that support QSFP28 DACs. The short fixed length and robust QSFP28-to-QSFP28 connectors simplify installation in dense rack environments and reduce failure points compared with longer, active cabling alternatives.

Suitable for

• High-density rack-to-rack or within-rack 100GbE links
• Short-reach connections between switches, routers and storage systems
• InfiniBand and Fibre Channel applications up to 100 Gbit/s
• Data center top-of-rack (ToR) and adjacent-rack interconnects

Key specifications

• Cable type: passive twinax copper direct attach cable
• Connector type: QSFP28 male to QSFP28 male
• Length: 0.5 meters
• Supported data rate: up to 100 Gbit/s (100GBase-CR4 compatible)
• Wire gauge: 30 AWG
• Compliance: MSA-compliant electrical and mechanical specifications
• Typical power consumption: passive (approx. 0.1 W system impact)

How to use

Install the QSFP28 DAC by aligning the QSFP28 connectors with the QSFP28 ports on the two devices and seating each end until the retention latch engages. Use the 0.5 m cable for short-distance links inside racks or between adjacent racks where active optical transceivers are not required. Verify that the connected devices support passive QSFP28 DAC cables and the chosen transmission protocol (Ethernet, Fibre Channel, InfiniBand). Perform link bring-up and check the host system for correct link speed and lane mapping.

Recommendations

Use this passive QSFP28 DAC for short, fixed-length connections to minimize latency and power draw. Avoid excessive bending near the connector boots, keep cable runs within the specified 0.5 m length, and ensure compatibility with the target hardware's QSFP28 passive DAC support before deployment.