DAC cable CBO QSFP28 to 4× SFP28 passive, 3 m

The BlueOptics DAC cable CBO QSFP28 to 4× SFP28 passive, 3 m is a direct-attach copper interconnect designed for short-reach, high-speed links in data center environments. The assembly terminates a single QSFP28 connector to four SFP28 connectors over a 3 meter passive copper twinax cable. It supports 25 Gb/s per lane and 100 Gb/s aggregated operation without optical transceivers, providing a low-latency and low-power cabling option for switch-to-switch, switch-to-server and server-to-server connections.

Advantages

This passive DAC cable delivers high bandwidth with minimal power consumption and reduced latency compared to optical solutions. The integrated QSFP28-to-4×SFP28 breakout design simplifies interconnection between 100 GbE ports and multiple 25 GbE ports while keeping installation and operational costs low. Its 3 m length is suitable for top-of-rack and short-reach patching, and the copper construction eliminates the need for separate optics and spare transceivers.

Suitable for

• Data center top-of-rack switch to server 25 GbE connections
• Aggregation between 100 GbE uplink ports and multiple 25 GbE downlinks
• Direct short-reach links in server racks and equipment cabinets
• Low-latency interconnects for virtualized environments and storage networks

Key specifications

• Connector type: QSFP28 to 4× SFP28 passive breakout
• Length: 3 meters
• Data rate: 25 Gb/s per lane, up to 100 Gb/s aggregated
• Media: Twinax copper passive cable
• Use case: Short-reach, direct-attach interconnect
• Latency and power: Low latency and reduced power compared to optical transceivers

How to use

Install the QSFP28 end into the 100 GbE port and insert the four SFP28 ends into the corresponding 25 GbE ports on switches, servers or routers. Ensure devices are powered down or follow hot-plug guidelines from the equipment manufacturer if supported. Verify link status and speed in device management interfaces after connection. No separate optics or transceivers are required; the cable provides a direct electrical connection between ports.

Recommendations

For reliable operation, route the cable to avoid sharp bends and mechanical strain and maintain appropriate airflow in racks. Use the 3 m length for short-reach top-of-rack or adjacent-rack connections; for longer distances consider optical solutions. Confirm compatibility with host equipment and firmware for passive DAC assemblies before deployment.