InfiniBand/fibre optic cable BlueOptics Q28-4S28-DAC-1M-MT-BL 1m QSFP28 4xSFP28 Male/Male

The BlueOptics Q28-4S28-DAC-1M-MT-BL is a 1 metre direct attach cable (DAC) with a QSFP28 plug on one end and four SFP28 plugs on the other, designed for short-reach high-speed links in racks and between adjacent racks. This passive twinax copper assembly supports 100GBase-CR4 or 4x25GBase-CR electrical signalling and is MSA-compliant, intended for use in data centre switches, routers and storage hardware that accept QSFP28 to 4xSFP28 DAC connections.

Advantages

The cable provides low latency and low power consumption typical of passive DAC solutions, enabling reliable 100 Gbit/s and 4x25 Gbit/s connections over a 1 m length. Built to MSA standards with 26 AWG conductors and rugged QSFP28/SFP28 connectors, it offers straightforward integration, minimal maintenance and an extended service life when used with compatible hardware. The passive design avoids additional active components, simplifying deployment and reducing total cost of ownership.

Suitable for

• Short-reach links inside racks and between adjacent racks
• 100GBase-CR4 or 4x25GBase-CR electrical connections
• Interconnects between switches, routers and storage systems
• InfiniBand, Ethernet, FCoE and Fibre Channel transceivers supporting DAC

Key specifications

• Length: 1 metre
• Connector type: QSFP28 (male) to 4 × SFP28 (male)
• Data rates supported: 100 Gbit/s (aggregate) or 4 × 25 Gbit/s
• Cable type: passive twinax copper (DAC), 26 AWG conductors
• Standards compliance: MSA-compliant QSFP28/SFP28 electrical pinout
• Typical use: short-distance electrical interconnects in data centres

How to use

Ensure both devices support passive QSFP28-to-SFP28 DAC cables and are configured for the intended link speed (100G or 4×25G). Power down or follow hot-plug guidance from your hardware vendor when inserting connectors if required. Insert the QSFP28 end into the QSFP28 port and each SFP28 plug into the corresponding SFP28 ports, ensuring secure seating and correct orientation. Verify link status in network equipment management interfaces and monitor for correct lane mapping and negotiated speed.

Recommendations

Use this DAC for short-distance, high-throughput connections inside racks or between adjacent racks. Avoid routing the cable through sharp bends or high-interference environments and follow manufacturer guidelines for hot-plugging and port compatibility to ensure optimal performance.