NVIDIA Mellanox MCC4Q30C-00A QSFP+ to QSFP+ Passive Copper InfiniBand Cable, 0.5 m (Lot of 10): This listing is a lot of 10 refurbished QSFP+ direct-attach copper (DAC) cables identified by MPN MCC4Q30C-00A. Each cable is a 0.5-meter passive copper QSFP+ to QSFP+ assembly carrying QDR (40 Gb/s) InfiniBand line rate. This is not an active optical cable, not a transceiver, and not an FDR (56 Gb/s) part. All 10 units are sold in refurbished, professionally tested working condition.
Engineering Context: Passive Direct-Attach Copper (DAC) implementation: there are no active electronics or optical transceivers in the cable. Signaling is sourced and recovered by the host port on each end, so signal integrity is the responsibility of the connected switch or HCA. At 0.5 m the cable presents minimal insertion loss and generous SI margin, which is why this length is favored for short, high-density intra-rack runs. Connector pin-out conforms to the SFF-8436 QSFP+ specification.
Deployment & Use Cases: Intra-rack fabric within HPC, storage, and high-throughput research clusters; switch-to-switch stacking between adjacent rack-mounted units; HCA-to-leaf links for compute nodes co-located with the top-of-rack switch; lab and test-bench environments where many short-reach DAC links are needed in a single bundle.
Technical Specifications:

MPN: MCC4Q30C-00A
Connectors: QSFP+ to QSFP+
Cable length: 0.5 meters
Cable type: Passive Direct-Attach Copper (DAC)
Conductor: Copper
Protocol: InfiniBand QDR
Per-port data rate: 40 Gb/s
Compliance: SFF-8436 QSFP+ pin-out
Quantity: 10 cables (lot)
Condition: Refurbished, tested working

Compatibility & Constraints: Compatible with Mellanox QDR / FDR-capable QSFP+ ports operating at QDR (40 Gb/s) line rate, including ConnectX-2 / ConnectX-3 HCAs and IS5000 / SX6000 family switches that auto-negotiate down to QDR. Not an FDR (56 Gb/s) cable; the part number is rated for QDR only. Not compatible with QSFP28 (100 Gb/s) ports or SFP+ (10 Gb/s) cages, and not a breakout cable. Because this is passive copper, port signaling integrity is the responsibility of the host; effective reach is limited to short intra-rack links.
Why TES IT-Solutions: TES specializes in refurbished NVIDIA Mellanox enterprise networking and ships short-reach DAC cables in vendor-original condition wherever possible. Each unit is tested by experienced technicians. Standard handling time is 1-3 business days. Visit TES IT-Solutions.