Passive Direct Attach Breakout Cable BlueOptics Q28-4S28-DAC-1M-IX-BL 100GBASE-CR4, 1 m, blue

Passive Direct Attach Breakout Cable BlueOptics Q28-4S28-DAC-1M-IX-BL 100GBASE-CR4, 1 m, blue is a 1‑metre twinax copper assembly engineered for short‑reach 100 Gbps interconnects. The cable implements a fixed 100GBASE‑CR4 electrical interface and splits into four lanes to connect a 100 Gbps port to four 25 Gbps ports or compatible QSFP28/SFP28 configurations. It is intended for direct server-to-switch or switch-to-switch connections in rack and adjacent-rack layouts where a low-latency, cost‑effective copper breakout solution is required.

Advantages

The passive twinax construction delivers low latency and deterministic signal performance without the need for separate optical transceivers, reducing power consumption and component count. As a factory-terminated assembly, it ensures consistent lane mapping and reliable electrical characteristics across the 1 m length. Its blue jacket provides easy visual identification in dense cabling environments, and the compact breakout design simplifies deployment in top-of-rack and adjacent-rack topologies.

Suitable for

• 100GBASE-CR4 short-reach links between switches
• Breakout connections from QSFP28 to four 25 Gbps ports
• Top-of-rack and adjacent-rack data center cabling
• High-density copper installations where optical transceivers are not required

Key specifications

• Interface type: 100GBASE-CR4 passive twinax breakout
• Length: 1 metre
• Color: blue jacket for identification
• Lane configuration: 4×25 Gbps lanes
• Connector arrangement: QSFP28 to 4×SFP28-compatible breakout
• Application: short-reach, copper direct-attach interconnect

How to use

Insert the QSFP28 end into the source 100 Gbps port and mate the four SFP28-compatible ends with the target 25 Gbps ports, ensuring correct alignment and secure seating. Route the cable to avoid sharp bends and mechanical strain; maintain the minimum bend radius specified by the manufacturer. No additional transceivers, power, or configuration is required at the cable level — link negotiation and speed configuration are managed by the connected devices according to supported standards.

Usage recommendations

For best performance, use this passive breakout cable for connections up to 1 m and in environments where temperature and electromagnetic conditions are within standard data center operating ranges. Verify compatibility with your switch and server port firmware and port mapping before deployment, and keep the cable free from kinks or tight bundles to preserve signal integrity.