The BlueOptics Direct Attach Breakout Cable 40G-DACP-QSFP4SFP3M is a passive copper assembly designed to convert a single QSFP port into four SFP+ channels. It supports 40GBASE-CR4 on the QSFP side and four 10GBASE-CR links on the SFP+ side, providing a cost-effective short-reach solution for aggregation, server and switch interconnects in data centres and network racks. The 3 m cable uses AWG30 conductors and is intended for use where passive QSFP-to-4×SFP+ breakout connectivity is required without additional transceivers.
Advantages
This passive breakout cable offers a direct, low-latency connection between a 40G QSFP port and four 10G SFP+ ports without the need for optical transceivers, reducing component count and power consumption. The fixed 3 m length and AWG30 copper construction provide reliable signal integrity for short-reach links within racks or between adjacent racks. Being a vendor-compatible passive assembly, it simplifies port breakout and aggregation tasks while maintaining the form factor and mechanical compatibility of QSFP and SFP+ interfaces.
Suitable for
- Short-reach server-to-switch connections within the same rack or adjacent racks
- Port breakout from a 40G QSFP interface to multiple 10G SFP+ interfaces for aggregation
- Top-of-rack and leaf-spine networking where passive copper interconnects are acceptable
- Environments seeking lower power consumption and reduced hardware count compared with transceiver-based links
When it may not be suitable
Because this is a passive copper breakout cable, it is intended for short-reach connections and will not support longer links or runs that require active signal conditioning or optical transceivers. It is not appropriate where galvanic isolation, extended distance, or fibre-based transmission is required. Compatibility should be checked with the specific switch or server vendor if strict vendor lock or port validation is enforced.
Key specifications
- Connectivity: QSFP (1) to SFP+ (4)
- Supported standards: 40GBASE-CR4 to 4×10GBASE-CR
- Cable type: Passive copper direct attach breakout
- Length: 3 m
- Conductor gauge: AWG30
- Typical use: Short-reach rack and data centre interconnects
How to use
Insert the QSFP end of the breakout cable into the 40G QSFP port on your switch or aggregation device and plug each SFP+ connector into the corresponding 10G ports on the target devices such as servers or downstream switches. Ensure devices are powered down or follow hot-swap guidelines from your hardware vendor if inserting into live systems. After connection, verify link status and speed in the device management interface; some equipment may require enabling breakout mode or configuring port mapping to present the four 10G channels.
What to consider before purchase
- Confirm that your switches and servers support passive QSFP-to-4×SFP+ breakout cables and do not require specific vendor transceivers.
- Ensure 3 m length is appropriate for rack layout and cable routing between devices.
- Verify that 10GBASE-CR electrical requirements match the endpoints and that AWG30 passive copper is suitable for the intended link distance.
- Check whether your hardware requires firmware settings or port mode changes to enable port breakout.
Usage recommendations
Use this BlueOptics 40G-DACP-QSFP4SFP3M cable for reliable short-distance breakout inside racks or between adjacent racks. Keep cable runs tidy and avoid sharp bends to maintain signal integrity. When deploying at scale, perform interoperability checks on a small set of ports before widespread rollout and monitor link status after installation.
