BlueOptics DAC-Q28-S28-5M InfiniBand fibre optic cable QSFP28 4x SFP28 5m

The BlueOptics DAC-Q28-S28-5M InfiniBand fibre optic cable QSFP28 4x SFP28 5m is a direct-attach cable designed for short-range, high-bandwidth connections in modern data center and networking setups. One end of the cable terminates in a QSFP28 plug while the opposite end provides four SFP28 plugs, enabling a single QSFP28 port to connect to four SFP28 ports without transceivers. The 5-metre length supports flexible rack-to-rack and within-rack installations where reliable, low-latency links are required.

Advantages

This passive cable provides a compact, low-power alternative to optical transceivers and patch cords, reducing equipment and operating costs. The QSFP28 to 4x SFP28 breakout format allows consolidation of high-density switch ports and simplifies cabling topology. Engineered for high signal integrity and stable throughput, the cable supports consistent InfiniBand performance and minimizes signal loss and crosstalk in short-distance connections.

Suitable for

• Top-of-rack and spine-leaf connections in data centers
• High-performance computing (HPC) clusters using InfiniBand fabrics
• Server-to-switch and switch-to-switch breakout links
• Network equipment lab testing and staging environments

Key specifications

• Connector type: QSFP28 plug on one end and four SFP28 plugs on the other
• Length: 5 metres
• Cable type: Direct Attach Copper/Passive or Active Cable form factor compatible with InfiniBand QSFP28/SFP28 ecosystems
• Supported interface: InfiniBand / 100GbE breakout compatible with QSFP28 and SFP28 ports
• Deployment: Short-reach, within-rack and adjacent-rack connections

How to use

Ensure both devices support the QSFP28 and SFP28 direct-attach cable configuration and that the ports are powered down or set to a safe state before insertion. Insert the QSFP28 end into the corresponding QSFP28 port until the latch engages, then insert each SFP28 plug into the target SFP28 ports. Verify link status via device LEDs or management interfaces and bring ports online according to your network configuration. For removal, release the latch mechanisms and pull straight out to avoid damaging the connectors.

Usage recommendations

Use the cable for short-distance, high-bandwidth connections where low latency and reduced power draw are priorities. Avoid tight bends and excessive mechanical stress; maintain the manufacturer’s minimum bend radius and keep connectors protected from dust when not in use. Confirm compatibility with switch and server vendor compatibility lists to ensure proper operation in InfiniBand or 100GbE breakout configurations.