# Network adapter Mellanox Technologies MCX4121A-ACAT internal PCI Express fiber interface

**URL:** https://aio.lv/en/product--oem-mcx4121a-acat--10494630
**Data updated:** 2026-02-18 14:37 (EET)
**Category:** Network Cards
**Manufacturer:** OEM
**Manufacturer code:** MCX4121A-ACAT
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 155.99 €
**Prices and availability valid until:** 2026-07-18 23:59
**Price without VAT (21%):** 128.92 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--oem-mcx4121a-acat--10494630

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 06.07.2026 | free |
| Pickup points | 09.07.2026 | 1.99 EUR |
| Courier delivery to door | 09.07.2026 | 4.99 EUR |

## Summary description

Internal network adapter Mellanox Technologies MCX4121A-ACAT with PCI Express host interface and fiber connectivity. Designed for wired network environments, it provides a fiber optic interface for high-speed links and is intended for installation in compatible servers or workstations. Suitable for data center, storage and high-throughput networking use cases where fiber connections are required.

## Long description

Internal network adapter Mellanox Technologies MCX4121A-ACAT with a PCI Express host interface and fiber connectivity provides a high-performance fiber optic link for servers and workstations. Based on the ConnectX-4 Lx EN family, this card supports multi-rate Ethernet from 1 Gb/s up to 50 Gb/s and is designed for wired network environments where fiber connections and low-latency, high-throughput links are required. The adapter implements RDMA acceleration and hardware offloads to reduce CPU overhead and improve overall application efficiency in virtualized and storage-heavy deployments.
Advantages
The MCX4121A-ACAT delivers flexible multi-rate Ethernet (1/10/25/40/50 Gb/s) on a single interface and includes support for RDMA and overlay network encapsulation/decapsulation to optimize data path performance. Using a PCI Express host connection and fiber physical interface, the adapter provides improved I/O isolation, reduced latency, and hardware-based offloads that lower CPU utilization for data center, cloud and analytics workloads. Its design targets scalability and compatibility with common server platforms for deployments that require reliable fiber links.
Suitable for
High-throughput data center networking and spine/leaf fabrics
Storage systems and SAN connectivity that require fiber optics
Virtualized servers and cloud infrastructure with heavy east–west traffic
Database and analytics platforms demanding low latency and high I/O
Environments using RDMA for accelerated data transfers
Key specifications
Host interface: PCI Express (x8 or compatible slot)
Physical interface: fiber optic transceiver (SFP+/QSFP-compatible form factor depending on module)
Supported link rates: 1 Gb/s, 10 Gb/s, 25 Gb/s, 40 Gb/s, 50 Gb/s
Controller family: ConnectX-4 Lx EN
Offload features: RDMA, hardware-based overlay encapsulation/decapsulation
Optimized for virtualized and cloud workloads with hardware I/O isolation
How to use
Install the Mellanox MCX4121A-ACAT into an available PCI Express slot on a compatible server or workstation following the host platform vendor’s procedures. Equip the card with the appropriate fiber transceiver module and connect to the fiber network using suitable fiber cabling and connectors. Install Mellanox drivers and firmware recommended for the server operating system to enable full feature support including RDMA and offload capabilities. Configure network settings, link speed, and driver parameters according to your environment and management tools.
Usage recommendations
Select fiber transceivers and cabling that match the supported link rates and the data center infrastructure. Keep firmware and drivers up to date to ensure compatibility and performance. For RDMA and high-performance workloads, verify server BIOS and OS settings (such as interrupt moderation and SR-IOV if applicable) to maximize throughput and reduce latency.

## 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 | 25 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

### How much does the Mellanox MCX4121A-ACAT internal PCIe fiber network adapter cost, and is it available for purchase?

The price is 155.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 2 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 06.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### 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 OEM 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 OEM 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/10494630/64393587_large.webp