Lenovo 00MM953 ConnectX-4 Lx 40GbE Single-Port QSFP+ PCIe 3.0 Adapter — the 00MM953 is a Lenovo FRU for a Mellanox ConnectX-4 Lx EN single-port 40GbE QSFP+ adapter card. MPN: 00MM953. This product IS a single-port QSFP+ network adapter; it is NOT a dual-port card, NOT a 100GbE adapter, NOT a CAPI/CXL accelerator. OEM: Lenovo (Mellanox-manufactured). Condition: refurbished.
Engineering Context
The 00MM953 uses the ConnectX-4 Lx ASIC, which provides hardware offloads for stateless TCP, RoCE v1/v2, NVMe-oF (RDMA), VXLAN/NVGRE/Geneve tunneling, and SR-IOV with up to 256 virtual functions per port. The single QSFP+ cage runs at 40Gb/s line rate (4x 10Gb/s NRZ lanes). Latency for two-sided RDMA write is in the sub-microsecond range. Host attach is PCIe 3.0 x8, providing roughly 64Gb/s of useful bidirectional bandwidth — sufficient for a single 40GbE port at full line rate.
Deployment & Use Cases
40GbE Top-of-Rack uplinks for virtualized workloads on Lenovo ThinkSystem SR-class, IBM System x, HP ProLiant Gen9, and Dell PowerEdge 13G/14G servers. RoCE-based hyperconverged storage (vSAN, Storage Spaces Direct, Nutanix). NVMe-oF initiators for NVMe over Fabrics targets. VMware ESXi, Microsoft Hyper-V, KVM, and OpenStack/Proxmox VE virtualized network fabrics with SR-IOV. Bare-metal database (OLTP) front-end and Hadoop/Spark cluster networking.
Technical Specifications
- OEM: Lenovo (Mellanox-manufactured)
- Part Number / FRU: 00MM953
- Controller: NVIDIA Mellanox ConnectX-4 Lx EN
- Network Ports: 1x QSFP+
- Speed: 40GbE (4x 10Gb/s NRZ)
- Host Interface: PCIe 3.0 x8
- RDMA: RoCE v1 and v2
- Tunneling Offloads: VXLAN, NVGRE, Geneve
- SR-IOV: Yes
- Bracket: Included
- Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Requires a PCIe 3.0 x8 (or wider) slot. The QSFP+ cage accepts Mellanox-coded 40GbE QSFP+ DAC, AOC, and SR4/LR4 transceivers. NOT a 100GbE adapter — the ConnectX-4 Lx 1-port QSFP+ tops out at 40GbE. NOT a dual-port card; this FRU is single-port. NOT a ConnectX-5 or ConnectX-6 — feature parity is limited to ConnectX-4 Lx generation. NOT compatible with PCIe 2.0 slots at full bandwidth. Driver and firmware support for the 00MM953 FRU comes from Lenovo for OEM-mode operation; vanilla NVIDIA Mellanox firmware may require explicit cross-flashing and is not supported by all host platforms.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS tests all 40GbE adapters for PCIe link training, port-level lane integrity, and link-up at 40GbE before dispatch. Lab-verified stock, 1–3 business day handling, global shipping. Technical consultation available for Lenovo and IBM 40GbE adapter deployments. Visit tes-itsolutions.com.