InfiniBand FDR passive copper direct-attach cable — the 670759-B24 is an HP-branded 2-meter QSFP+ to QSFP+ passive copper DAC for InfiniBand FDR (Fourteen Data Rate) interconnects at 56Gb/s aggregate (4× 14Gb/s lanes). MPN: 670759-B24. This product IS a fixed-length 2m passive copper cable assembly with two integrated QSFP+ connectors; it is NOT an active optical cable, NOT a transceiver, NOT a breakout cable, and NOT a longer-reach FDR cable. OEM: HP. Condition: refurbished.
Engineering Context
FDR signals at 14.0625 Gb/s per lane using 64b/66b encoding across 4 differential pairs, yielding 56Gb/s aggregate signaling and ~54.54 Gb/s effective data rate. Passive copper DAC at 2m is well within the FDR copper reach limit (typically 3–5m for passive at 14Gb/s). The cable provides EMI immunity within data center cable trays, draws no power (no transceiver electronics), and contributes near-zero added latency compared to AOC. Bend radius and pull tension follow standard QSFP+ DAC specifications.
Deployment & Use Cases
InfiniBand FDR HPC compute fabric — ConnectX-3 / ConnectX-3 Pro VPI adapters to Mellanox SX6000 series FDR switches. GPU compute clusters using FDR for MPI traffic. Lustre and BeeGFS parallel filesystem interconnects. Short intra-rack server-to-Top-of-Rack switch runs at 2m. FDR-attached storage targets. Mellanox Grid Director 4036E / SX6018 / SX6036 FDR switch deployments.
Technical Specifications
OEM: HP
Part Number: 670759-B24
Cable Type: Passive copper Direct-Attach (DAC)
Connectors: QSFP+ to QSFP+ (point-to-point)
Protocol: InfiniBand FDR
Aggregate Rate: 56 Gb/s (4× 14.0625 Gb/s lanes)
Length: 2 m
Encoding: 64b/66b
Power: Passive (no power draw)
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Constraints
Compatible with HP and Mellanox FDR InfiniBand switches and ConnectX-3 / ConnectX-3 Pro VPI adapters. Will operate at FDR10 (40Gb/s) when one end runs older FDR10 hardware. NOT an active optical cable — passive copper has a hard reach limit; for runs over ~5m, an FDR AOC is required. NOT compatible with EDR (100Gb/s) or HDR (200Gb/s) switches at native EDR/HDR rate; will fall back to FDR or fail link training depending on switch policy. NOT a 1:4 breakout cable — this is a direct 1:1 QSFP+ assembly. Fixed 2m length. Not for Ethernet QSFP+ 40GbE use without explicit switch firmware support for QSFP+ DAC interoperation.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS tests all InfiniBand FDR DAC cables for full-lane link training at 14Gb/s per lane and connector continuity prior to dispatch. Lab-verified stock, 1–3 business day handling, global shipping. Technical consultation available for HPC InfiniBand fabric design. Visit tes-itsolutions.com.