InfiniBand/fibre optic cable BlueOptics Q28-4S28-DAC-3M-PS-BL 3m QSFP28 4x SFP28 Male/Male

The BlueOptics Q28-4S28-DAC-3M-PS-BL is a 3 m direct attach cable with a QSFP28 plug on one end and four SFP28 plugs on the other. Designed for short-range electrical connectivity in rack and adjacent-rack installations, this 26 AWG twinax cable supports aggregated 100GBase-CR4 or 4x25GBASE-CR links and is intended for use with equipment that accepts QSFP28-to-4xSFP28 breakout connections. The cable is suitable for high-speed Ethernet, Fibre Channel, FCoE and InfiniBand applications where a passive DAC solution is appropriate.

Advantages

This passive QSFP28 to 4xSFP28 direct attach cable provides low latency and low power consumption for short-distance connections. It is manufactured to MSA-compliant electrical and mechanical specifications and uses high-quality components to offer consistent signal integrity and long service life. The passive design reduces failure points by avoiding active electronics in the cable and simplifies installation in dense rack environments.

Suitable for

• Interconnecting switches and routers within the same rack or adjacent racks
• Connecting storage systems to top-of-rack switches supporting 100G breakout
• Short-reach InfiniBand or Ethernet links where passive DACs are supported
• High-density server and blade deployments requiring breakout connectivity

Key specifications

• Length: 3 meters
• Connector A: QSFP28 male
• Connector B: 4 × SFP28 male (breakout)
• Cable type: Passive twinax copper (DAC), 26 AWG
• Supported protocols: 100GBase-CR4, 4×25GBASE-CR, Ethernet, FCoE, Fibre Channel, InfiniBand
• Power consumption: passive (typical very low power draw)
• Compliance: MSA QSFP28 breakout compatibility; meets common industrial directives (CE/RoHS/FCC where applicable)

How to use

Ensure both devices support passive QSFP28-to-4xSFP28 breakout cables and the intended transmission protocol. Insert the QSFP28 end into the QSFP28 port and the SFP28 ends into the corresponding SFP28 ports on the destination device. Verify link negotiation and speed settings on both ends via the management interface of the switches or servers. Avoid excessive bending near the connectors and route the cable to prevent mechanical strain during rack movement or equipment servicing.

Recommendations

Use this 3 m DAC for short interconnects inside racks or between adjacent racks; confirm vendor support for passive DACs in your hardware and, if needed, request a test sample to validate compatibility before large-scale deployment.