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Single-port QSFP28 network card, low-profile, silver bracket

NVIDIA

NVIDIA MCX555A-ECAT network card 100Gb/s QSFP28 PCIe 3.0 x16

SKU CH-MDX5-TRDR9 MPN MCX555A-ECAT

Single-port QSFP28 adapter delivering 100 Gb/s InfiniBand or Ethernet over PCIe 3.0 x16 with RDMA offload

  • SpeedInfiniBand: SDR/DDR/QDR/FDR/EDREthernet: 10/25/40/50/100 Gb/
  • ConnectorsSingle-port QSFP28
  • InterfacePCI Express Connectors: PCIe Gen 3.0 x16; SerDes @ 8.0GT/s
  • Dimensions2.71 in. x 5.6 in. (68.90mm x 142.24 mm) - low profile
  • 100 Gb/s InfiniBand and Ethernet throughput via single QSFP28 port
  • PCIe 3.0 x16 interface with 8.0 GT/s SerDes for high bandwidth
  • Sub-600 ns latency accelerates HPC and ML workloads
  • RDMA and NVMe over Fabric offloads reduce CPU overhead
  • Low-profile 68.90 mm × 142.24 mm form factor fits dense servers

ConnectX-5 adapter for HPC and cloud

The MCX555A-ECAT is a single-port QSFP28 network card built on the ConnectX-5 controller. It delivers 100Gb/s InfiniBand EDR and 100GbE connectivity over a PCIe 3.0 x16 interface. The low-profile bracket fits dense server chassis used in high-performance computing, machine learning and data analytics clusters.

RDMA offload and NVMe acceleration

Hardware offloads for MPI, SHMEM and PGAS reduce CPU overhead in message-passing workloads. RDMA Write and Read operations execute out of order, while network and PCIe atomic operations extend remote memory semantics. NVMe over Fabric offload moves storage commands onto the adapter, freeing host cycles for compute tasks.

PCIe 3.0 x16 bandwidth ceiling

The Gen 3.0 x16 link runs at 8.0GT/s per lane, capping theoretical throughput below the wire-rate 100Gb/s potential of the QSFP28 port. Sustained performance depends on host PCIe topology and CPU lane allocation. The card does not support PCIe 4.0 or 5.0 signalling rates.

Highlights

  • 100 Gb/s InfiniBand and Ethernet throughput via single QSFP28 port
  • PCIe 3.0 x16 interface with 8.0 GT/s SerDes for high bandwidth
  • Sub-600 ns latency accelerates HPC and ML workloads
  • RDMA and NVMe over Fabric offloads reduce CPU overhead
  • Low-profile 68.90 mm × 142.24 mm form factor fits dense servers

Specifications

BrandNVIDIA
ModelConnectX-5 InfiniBand/Ethernet Adapter Cards
Part NumberMCX555A-ECAT
SpeedInfiniBand: SDR/DDR/QDR/FDR/EDREthernet: 10/25/40/50/100 Gb/s
ConnectorsSingle-port QSFP28
InterfacePCI Express Connectors: PCIe Gen 3.0 x16; SerDes @ 8.0GT/s
Dimensions2.71 in. x 5.6 in. (68.90mm x 142.24 mm) - low profile
Shipping weight0.23 kg
Package size197 × 155 × 35 mm

Questions about this item

Will the QSFP28 transceiver need periodic replacement?

The transceiver is a separate module; the card itself has no user-serviceable parts and requires no scheduled maintenance.

What limits sustained 100 Gb/s throughput first?

The PCIe 3.0 x16 host interface with 8.0 GT/s SerDes sets the maximum sustained bandwidth ceiling.

How loud and hot does the card get under continuous load?

The low-profile 68.90 mm x 142.24 mm design uses passive cooling, so it adds no fan noise and relies on chassis airflow for heat dissipation.

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