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Network Cards

Network cards slot into a server’s PCIe slot,or direct into motherboard to provide higher-speed network connectivity. They are split into three categories - NIC (Network Interface Cards), LOM (LAN On Motherboard) and HBA (host Bus Adapter). These expansion cards are one of the most flexible ways to expand your server’s networking capabilities at just a fraction of the cost.

At ITinStock, we stock a huge range of refurbished network cards  from leading brands such as Intel, Mellanox, Broadcom and HPE, with speeds from 1GbE through to 100GbE. Browse our selection or contact us for help finding the right network card for your server.

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The Benefits of Upgrading Your Server's Network Card

Adding or upgrading a network card can dramatically boost the bandwidth of your business. When it comes to running ageing tech, the on board 1GbE NIC is the single biggest bottleneck to application performance. This is especially the case in virtualised environments, storage-intensive workloads, and data centre applications where network throughput directly limits what the server can do.

The most common upgrade path is from 1GbE to 10GbE, which delivers ten times the raw bandwidth of a standard Gigabit connection. 10GbE eliminates the network as a bottleneck for storage I/O, especially where SSDs or NVMe drives are in use. For organisations scaling further, 25GbE adapters (that use the SFP28 interface) offer a straightforward next step up with roughly the same cabling infrastructure, whilst 100GbE adapters using QSFP28 are available for the most demanding high-performance computing.

Two key features to look for in enterprise server NICs are SR-IOV (Single Root I/O Virtualisation) and RDMA (Remote Direct Memory Access). SR-IOV allows a single NIC to provide multiple functions directly to individual virtual machines, which basically reduces CPU workload. Meanwhile, RDMA allows servers to transfer data directly between memory without the CPU being involved, which gives a high output for storage and clustering. Port counts can also range from single-port through to quad-port, and most enterprise NICs are available in both full-height and low-profile bracket configurations to suit different server chassis form factors.

Why Choose Refurbished Network Cards from ITinStock?

We stock a wide range of refurbished network cards at ITinStock, and we’re happy to discuss your specific requirements to help identify the right card for your server and workload. Every card undergoes rigorous testing to ensure it functions optimally before being despatched. We work with our couriers to arrange fast delivery to the UK and worldwide. Our expert support team are on hand to assist with any requirements, from pre-purchase compatibility advice through to post-delivery support.

Complement Your Setup

Get the most from your network card upgrade with these complementary IT components:

  • Rack Servers Refurbished Dell PowerEdge, HPE ProLiant, and Fujitsu PRIMERGY rack servers to pair with your network card upgrade for a complete, high-performance server solution.
  • Networking Equipment 10GbE and 25GbE Ethernet switches to connect your upgraded servers into a high-speed network fabric.
  • Memory (RAM) We stock DDR4 & DDR5 RAM to help you maximise your system memory.

Frequently Asked Questions

What network card speeds does ITinStock stock?
We stock server network cards across a range of speeds to suit different infrastructure requirements. This includes 1GbE single and quad-port RJ45 cards based on Intel I350 and I210 controllers, 10GbE dual and quad-port cards in both RJ45 (Intel X540, X550) and SFP+ (Intel X520, X710, 82599; Mellanox ConnectX-3 and ConnectX-4 Lx; Broadcom BCM57810) configurations, and 25GbE dual-port SFP28 cards including the Mellanox ConnectX-4 Lx and ConnectX-5, Intel E810, and Broadcom BCM57414. We also stock select 40GbE and 100GbE adapters where available. Please contact our team for current stock levels or to discuss a specific model or configuration.

How do I know which network card is compatible with my server?
There are three key compatibility factors to check before purchasing a network card. First, the PCIe slot: confirm that your server has a free PCIe slot of the appropriate lane width. Most 10GbE and 25GbE NICs require a PCIe 3.0 x8 slot for full line-rate performance; installing a card in a narrower or older-generation slot may reduce throughput. Second, the bracket height: rack servers typically use low-profile (half-height) cards, while tower servers use full-height cards. Most enterprise NICs are available with both bracket types, and many include both in the box. Third, the server’s HCL (Hardware Compatibility List): major server vendors including Dell, HPE, and Fujitsu publish supported NIC lists for each server model; using an HCL-validated card ensures driver support and firmware compatibility with the server’s BIOS and management stack. If you’re unsure, please contact our team with your server model and we’ll advise on compatible options.

What is the difference between an SFP+ and an RJ45 network card?
RJ45 network cards use the same standard copper connectors as everyday Ethernet and connect using Cat6 or Cat6a cabling up to 100 metres. They are the simplest upgrade option for environments with existing copper infrastructure, as no additional transceivers are required. SFP+ cards use small form-factor pluggable ports that accept either optical transceiver modules or low-cost Direct Attach Copper (DAC) cables for short-reach rack-to-rack connections of up to around 5 metres. In data centre environments, SFP+ is the more common choice at 10GbE and above because DAC cables are very cost-effective for short distances, and optical transceivers provide flexibility for longer runs. RJ45 10GbE cards also consume more power and generate more heat than SFP+ equivalents, which can be a consideration in high-density deployments. For 25GbE and above, SFP28 (25G) and QSFP28 (100G) are the standard interfaces, with RJ45 options available but less common at these speeds.

Do I need a special network card for a virtualised server environment?
Not necessarily but choosing a NIC with virtualisation-specific features makes a significant difference to performance and CPU efficiency in virtualised environments. SR-IOV (Single Root I/O Virtualisation) is the most important feature to look for: it allows the NIC to present virtual functions directly to individual VMs, bypassing the hypervisor switch for each VM’s network traffic, dramatically reducing CPU overhead and latency compared to a standard software-switched virtual network. VMDq (Virtual Machine Device Queues) is a related Intel technology that improves packet sorting efficiency in virtualised environments without requiring full SR-IOV. Both features are supported on Intel X710, X550, and E810 series cards, as well as on Mellanox ConnectX-4 and later adapters. For VMware environments specifically, selecting a card on VMware’s HCL and with a native ESXi driver is recommended for optimal performance and supportability.

Can I use a refurbished network card in a production server environment?
Yes. Refurbished network cards from enterprise manufacturers such as Intel, Mellanox, and Broadcom are pre-owned components that have been inspected, tested, and verified to be in full working order before resale. At ITinStock, every card undergoes rigorous testing to ensure it operates reliably. The hardware itself is identical to new — NIC chipsets have no mechanical wear components and are not subject to the same ageing considerations as drives or fans. The key practical difference is that a refurbished card is unlikely to come with original retail packaging or accessories, and the product may have cosmetic marks. Functionally, a well-tested refurbished NIC from a reputable supplier delivers the same performance, driver support, and feature set as a new equivalent, at a substantially lower cost. Refurbished enterprise NICs from Intel, Mellanox, and Broadcom are widely used in production data centre environments.

Find Your Ideal Network Card Today

Browse our complete range of refurbished network cards or contact our team for expert advice on selecting the right card for your server and workload from ITinStock.

Phone: +44 (0)20 4631 3555
Email: hello@itinstock.com

Contact our team today

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