 
|
NVIDIA ConnectX-4 Lx EN MCX4121A-XCAT – Dual-Port 10GbE SFP28 Adapter Card with RoCE Virtualization Offloads
Product Details:
| Brand Name: | Mellanox |
| Model Number: | MCX4121A-XCAT |
| Document: | connectx-4-lx-en-card.pdf |
Payment & Shipping Terms:
| Minimum Order Quantity: | 1pcs |
|---|---|
| Price: | Negotiate |
| Packaging Details: | outer box |
| Delivery Time: | Based on inventory |
| Payment Terms: | T/T |
| Supply Ability: | Supply by project/batch |
|
Detail Information |
|||
| Products Status: | Stock | Application: | Server |
|---|---|---|---|
| Condition: | New And Original | Type: | Wired |
| Max Speed: | 25Gb/s | Name: | MCX4121A-XCAT Mellanox Network Card 25Gbps SFP28 QSFP28 For Server |
Product Description
Dual-port SFP28 10GbE Ethernet adapter card — delivering low latency, RDMA over Converged Ethernet (RoCE), and hardware-based virtualization offloads. Ideal for cloud, Web 2.0, database, and storage platforms requiring cost-effective 10GbE connectivity with advanced acceleration.
The NVIDIA ConnectX-4 Lx EN MCX4121A-XCAT is a dual-port 10GbE Ethernet adapter card designed for data centers that demand high throughput, sub-microsecond latency, and efficient server utilization. Built on the proven ConnectX-4 Lx architecture, this adapter supports 10GbE and 1GbE speeds, making it a flexible solution for enterprise and cloud environments. It offloads transport operations, overlay network encapsulation (VXLAN, NVGRE), and provides hardware-based I/O virtualization (SR-IOV). The MCX4121A-XCAT includes RoCE (RDMA over Converged Ethernet) for low-latency memory access, PeerDirect for GPU communication acceleration, and comprehensive management interfaces including NC-SI for BMC integration.
Two SFP28 ports supporting 10GbE and 1GbE speeds. Interoperable with standard Ethernet switches.
Low-latency, high-performance RDMA services over Layer 2 and Layer 3 networks.
SR-IOV supports up to 256 Virtual Functions (VFs) and 8 Physical Functions per port for VM isolation.
Hardware encapsulation/de-encapsulation for VXLAN, NVGRE, and GENEVE – preserving native performance.
TCP/UDP stateless offloads, LSO/LRO, checksum offload, RSS/TSS, and intelligent interrupt coalescence.
NC-SI over MCTP (SMBus/PCIe) for BMC integration, remote boot over iSCSI, PXE, and UEFI.
The ConnectX-4 Lx EN ASIC delivers 75 million packets per second message rate and sub-microsecond latency. Key innovations include:
- PeerDirect (GPUDirect) – Eliminates unnecessary PCIe data copies between GPU and CPU, accelerating HPC and AI workloads.
- Extended Reliable Connected (XRC) & Dynamically Connected Transport (DCT) – Scales RDMA to tens of thousands of nodes.
- On-Demand Paging (ODP) – Registration-free RDMA memory access, simplifying application development.
- Advanced Congestion Control – IEEE 802.1Qau (QCN), ETS, PFC for lossless RoCE fabrics.
High-density virtualization hosts with 10GbE connectivity, requiring low overhead and high packet rates.
iSCSI, NVMe-oF, and SMB Direct over RoCE for high-performance block/file access.
Low-latency RDMA accelerates distributed databases (e.g., Cassandra, MongoDB) and big data frameworks.
PeerDirect enables direct GPU-to-GPU communication without CPU involvement, ideal for AI training.
The MCX4121A-XCAT is compatible with a wide range of operating systems: RHEL/CentOS, Ubuntu, Windows Server, FreeBSD, VMware ESXi, and Citrix XenServer. It supports standard 10GbE SFP+ optics, passive DAC cables up to 5m, and active optical cables. The adapter integrates seamlessly with NVIDIA Spectrum switches and any standards-based 10GbE/25GbE infrastructure. Software support includes OFED (OpenFabrics Enterprise Distribution) and WinOF-2 for Windows.
| Category | Specification |
|---|---|
| Model | MCX4121A-XCAT |
| Form Factor | Low-profile PCIe add-in card (14.2cm x 6.9cm without bracket). Ships with tall bracket mounted, short bracket included. |
| Ports | 2x SFP28 (10GbE / 1GbE) |
| Supported Speeds | 10GbE, 1GbE |
| Host Interface | PCIe 3.0 x8 (compatible with x16, x4, x2, x1; auto-negotiated) |
| Message Rate | 75 million packets per second (Mpps) |
| Latency | Sub-microsecond (typical) |
| Virtualization | SR-IOV: up to 256 Virtual Functions, 8 Physical Functions per port |
| RoCE Support | Yes – RDMA over Converged Ethernet (RoCE) |
| Overlay Offloads | VXLAN, NVGRE, GENEVE hardware encapsulation/de-encapsulation |
| CPU Offloads | TCP/UDP checksum offload, LSO/LRO, RSS, TSS, VLAN insertion/stripping |
| Management Interfaces | NC-SI over MCTP (SMBus/PCIe), BMC interface, SDN eSwitch management, SPI flash, JTAG |
| Remote Boot | PXE, UEFI, iSCSI remote boot |
| Power Consumption | Not publicly specified – please confirm before ordering |
| Operating Temperature | 0°C to 55°C (typical) |
| Standards | IEEE 802.3ae (10GbE), 802.3az EEE, 802.1Qbb PFC, 802.1Qaz ETS, 1588v2, PCIe Gen 3.0 |
| RoHS | Compliant |
| OPN (Ordering Part Number) | Ports | Max Speed | Interface | Key Feature |
|---|---|---|---|---|
| MCX4121A-XCAT | 2 | 10GbE | SFP28 | Dual-port, Host Management, UEFI enabled |
| MCX4111A-XCAT | 1 | 10GbE | SFP28 | Single-port, low profile |
| MCX4121A-ACAT | 2 | 25GbE | SFP28 | Dual-port 25GbE |
| MCX4131A-BCAT | 1 | 40GbE | QSFP28 | 40GbE single-port |
| MCX4131A-GCAT | 1 | 50GbE | QSFP28 | 50GbE single-port |
Delivers line-rate throughput and low latency for virtualized and bare-metal servers.
Works with standard Linux distributions, Windows, and VMware – no vendor lock-in.
VXLAN/NVGRE offloads protect CPU resources as overlay networks become ubiquitous.
Hong Kong Starsurge offers competitive pricing, warranty support, and fast worldwide delivery.
Hong Kong Starsurge provides end-to-end support for NVIDIA/Mellanox adapters, including compatibility verification, firmware updates, and technical troubleshooting. Standard warranty aligns with NVIDIA's limited hardware warranty (1 year return-and-repair). Extended support options are available upon request. Our team can assist with driver installation, performance tuning, and integration into existing server environments.
| Category | Supported Options |
|---|---|
| Operating Systems | RHEL/CentOS, Ubuntu, Windows Server 2016/2019/2022, FreeBSD, VMware ESXi 6.5+, Citrix XenServer |
| Switches | NVIDIA Spectrum series, Cisco Nexus, Arista, Juniper, any standards-based 10GbE/25GbE switch |
| Cables and Optics | SFP+ passive DAC (up to 5m), SFP+ active optical cable, 10GBASE-SR (850nm), 10GBASE-LR (1310nm) |
| Management Protocols | NC-SI, MCTP over PCIe/SMBus, PLDM for monitoring and firmware update |
- Confirm server has an available PCIe x8 (or larger) slot – Gen 3.0 or higher.
- Determine required cable type: passive DAC, active optical, or optical transceivers for your distance.
- Verify operating system driver availability from NVIDIA/Mellanox official site.
- Check if your switch supports 10GbE SFP+ modules (most modern switches do).
- For BMC integration, ensure your motherboard supports NC-SI over SMBus or PCIe.
Dual-port 25GbE adapter for higher bandwidth requirements.
48x 25GbE + 12x 100GbE top-of-rack switch for leaf/spine fabrics.
Passive copper direct-attach cables for 10GbE/25GbE connections.
- RoCE Deployment Guide for ConnectX-4 Series
- SR-IOV Configuration on VMware ESXi with Mellanox Adapters
- VXLAN Hardware Offload Best Practices
Hong Kong Starsurge Group Co., Limited is a technology-driven provider of network hardware, IT services, and system integration since 2008. Serving government, healthcare, manufacturing, finance, education, and enterprise clients worldwide. We deliver switches, NICs, wireless solutions, IoT systems, and custom software with multilingual support and global delivery. With a customer-first approach, Starsurge ensures reliable quality, responsive service, and tailored network infrastructure solutions.