# Network card MELLANOX MCX4121A-XCAT internal PCI Express, fiber interface, wired

**URL:** https://aio.lv/en/product--mellanox-mmcx4121axcat--4060639
**Data updated:** 2026-03-20 09:44 (EET)
**Category:** Network Cards
**Manufacturer:** MELLANOX
**Manufacturer code:** MMCX4121AXCAT
**EAN:** 7290107197878
**Warranty:** 2 Years
**Availability:** Out of stock

## Summary description

MELLANOX MCX4121A-XCAT is an internal wired network card with a PCI Express host interface and fiber physical interface. It supports Ethernet networking standards including IEEE 802.1Q, 802.1AX and various QoS and energy-efficient protocols. Intended for servers and workstations requiring fiber connectivity, VLAN tagging, link aggregation and advanced traffic management.

## Long description

MELLANOX MCX4121A-XCAT is an internal wired network card designed for servers and workstations that require high-performance fiber connectivity via a PCI Express host interface. The adapter supports multi-rate Ethernet connectivity (1/10/25/40/50 Gb/s) and includes an advanced ConnectX-4 Lx EN network controller that provides hardware acceleration for RDMA, overlay network encapsulation/decapsulation and other offloads. The card implements industry networking standards such as IEEE 802.1Q for VLAN tagging and IEEE 802.1AX for link aggregation, and supports QoS and energy-efficient Ethernet protocols for efficient network resource use.
Advantages
The MCX4121A-XCAT offers multi-rate fiber connectivity and a PCI Express host interface for compatibility with modern server platforms. Hardware-based I/O isolation and offload capabilities reduce CPU overhead and improve application performance in virtualized and data-intensive environments. Support for RDMA and overlay networks encapsulation/decapsulation enables lower latency and greater throughput for storage, database and cloud workloads. Standards-based VLAN tagging, link aggregation and QoS features simplify integration in managed network infrastructures.
Suitable for
High-performance servers in data centers and private clouds
Virtualized environments requiring RDMA and hardware offloads
Storage and database systems needing low-latency fiber connectivity
Network infrastructures using VLANs, link aggregation and QoS policies
Applications that require multi-rate Ethernet (1/10/25/40/50 Gb/s)
Key specifications
Connectivity: Wired fiber interface
Host interface: PCI Express (PCIe)
Supported speeds: 1/10/25/40/50 Gigabit Ethernet
Network controller: ConnectX-4 Lx EN
Offload features: RDMA, overlay network encapsulation/decapsulation, hardware I/O isolation
Supported standards: IEEE 802.1Q (VLAN), IEEE 802.1AX (link aggregation), QoS and energy-efficient Ethernet protocols
How to use
Install the MCX4121A-XCAT into an available PCI Express slot on a compatible server or workstation following the chassis and motherboard manufacturer guidelines. Connect fiber cables to the card's fiber interface and configure link speed and duplex settings as required by the network. Install vendor drivers and firmware updates from the manufacturer to enable full functionality, including RDMA and overlay encapsulation features. Configure VLANs, link aggregation and QoS in the host operating system or network management platform to match your network design.
Usage recommendations
Ensure the host system firmware and operating system are up to date and use Mellanox-provided drivers for best compatibility. For RDMA and low-latency workloads, verify NIC offloads are enabled and tune network stack parameters according to application requirements. Use appropriate fiber transceivers and cabling rated for the intended speed (1/10/25/40/50 Gb/s) and verify SFP/QSFP compatibility with the ConnectX-4 Lx EN controller.

## Specifications

### Ports & interfaces

| Feature | Value |
|---|---|
| Connectivity technology | Wired |
| Interface | Fiber |
| Host interface | PCI Express |
| Internal | Yes |
| Fiber ports quantity | 2 |
| Fiber optic connector | SFP28 |
| PCI version | 3.0 |

### Bandwidth

| Feature | Value |
|---|---|
| Data transfer rate | 10 GT/s |

### Network

| Feature | Value |
|---|---|
| Networking standards | IEEE 802.1Qau, IEEE 802.3az, IEEE 802.3ad, IEEE 802.1Qbg, IEEE 802.1Qbb, IEEE 802.1Qaz, IEEE 802.1Q, IEEE 802.1AX |

### Performance

| Feature | Value |
|---|---|
| Windows operating systems supported | Y |
| Other operating systems supported | FreeBSD |

### Weight & dimensions

| Feature | Value |
|---|---|
| Height | 69 mm |
| Width | 142 mm |

## FAQ

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All MELLANOX products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized MELLANOX service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

### How can I tell if this product suits my needs?

When making a choice, we recommend paying attention to the key features: connectivity technology, interface, host interface, networking standards, compatibility with your devices or usage conditions, material quality, functionality, and warranty terms. These characteristics will help you determine how well the model meets your needs.

## Image

https://aio.lv/img/cache/product/4060639/54736591_large.webp