NVIDIA Mellanox MC2309124-004 40GbE QSFP+ to 4x10GbE SFP+ Passive Copper Splitter Cable, 4m (Lot of 4): This is a 4-meter passive direct attach copper (DAC) hybrid splitter that breaks one 40GbE QSFP+ port into four independent 10GbE SFP+ links. The cable is a fixed-length integrated assembly, not a transceiver pair. Sold as a lot of 4 refurbished units.
Engineering Context
The MC2309124-004 uses twinaxial copper conductors in a 1:4 hybrid splitter topology. The host QSFP+ end aggregates 4 lanes at 10.3125 Gb/s NRZ (40 Gb/s total); each SFP+ branch carries one of those lanes at 10GbE. As a passive cable it draws no power and adds negligible latency. Lane mapping is fixed at the connector paddle cards, so each SFP+ branch is logically tied to one of the four QSFP+ lanes.
Deployment & Use Cases
Quadrupling effective port density on 40GbE switches by serving four 10GbE hosts from one QSFP+ switch port. Connecting 10GbE ConnectX adapters to 40GbE Top-of-Rack switches. Storage spine aggregation feeding multiple 10GbE targets. Mixed-speed leaf designs and migration paths from 10GbE to 40GbE.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MC2309124-004
Cable Type: Passive Direct Attach Copper Hybrid Splitter (1:4)
Form Factor: QSFP+ to 4x SFP+
Length: 4m
Host Data Rate: 40GbE (4x 10.3125 Gb/s NRZ)
Branch Data Rate: 10GbE per branch
Conductor: Twinaxial Copper
Protocol: Ethernet (40GbE host / 10GbE branch)
Lot Quantity: 4 units
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with Mellanox SX1000-series 40GbE switches and ConnectX-3/3 Pro/4 Lx EN adapters that accept Mellanox-coded passive splitter DACs. Requires the QSFP+ host port to be configured for 4x10GbE breakout in the switch. Not compatible with 100GbE QSFP28 host ports (different PHY); for 100G to 4x25GbE use a QSFP28-to-4xSFP28 cable instead. Not for InfiniBand FDR/EDR ports without protocol reconfiguration. Fixed 4m length; non-detachable connectors.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS verifies link bring-up on all four branches and paddle-card EEPROM integrity before shipment. Visit tes-itsolutions.com for 40GbE/10GbE migration consultation. Stocked in the EU with 1–3 day handling and global shipping.