# Buacoz Intel I226 4-Port 2.5GbE NIC: Who It Fits and Who Should Skip It > Intel I226 4-port 2.5GbE PCIe x4 NIC: bandwidth math, OS support, thermals, and who should skip it. Amazon price as captured in Aug 2026. Tags: network-card, buacoz, intel-i226, 2-5gbe, pcie-x4, pfsense, unraid, nas Source: https://www.amazon.co.jp/dp/B0DNJVBHSW Article page: https://web-autoai.com/articles/buacoz-25g-4-intel-i226-pci-e-x4-2500m-rj45-lan-windows-10?lang=en Prices and ratings change over time — check the article page for the current values. --- The Buacoz 2.5G 4-Port Server Network Card packs four Intel I226 controllers onto a single PCI Express X4 card, supporting 10/100/1000/2500 Mbps and shipping with both full-height and low-profile brackets. It is not a product for making one link faster — it is a product for solving "I don't have enough ports. " ## Overview Port count is the whole point here. Four 2.5GbE RJ45 ports built on Intel I226 silicon occupy one X4 slot, which is what turns an ordinary desktop board with a single onboard NIC into a router, firewall, or multi-segment NAS host. As captured in June 2026, the Amazon. co. That is a small sample, so judge it less by the star average and more by the configuration itself: Intel controllers are recognized by in-box drivers across Windows, Linux, and BSD, which is a meaningfully different experience from cheap four-port cards using unknown silicon. It is a sharply targeted product — excellent if your use case matches, plainly excessive if it doesn't. ## Compatibility Guide The physical interface is PCI Express X4. It works in X4, X8, and X16 slots. It will not fit an X1 slot unless that slot is open-ended at the rear, so open your case and check before ordering. PCIe 3.0 and 2.0 are listed as supported generations. On bandwidth: 2.5 Gbps × 4 ports is roughly 10 Gbps aggregate. A PCIe 3.0 x4 link (around 3 GB/s effective) has ample headroom even with all four ports saturated. On older PCIe 2.0 boards, or in slots electrically wired to only x1 or x2 lanes, all-port saturation could bottleneck. Check your motherboard manual for the electrical lane count of the slot you plan to use. Listed OS support covers Windows 10/11, Windows Server 2019/2022, Linux, FreeBSD, OpenWrt, and pfSense. **macOS is not supported. ** PXE boot is supported, and iKuai, Unraid, and Synology DSM are named as target environments — though retail Synology units can reject unofficial NICs, so a general-purpose OS such as Unraid or TrueNAS is the safer path. Both brackets are included, so ATX towers, 1U/2U rack chassis, and slim Mini-ITX cases are all viable. Do watch physical clearance: four RJ45 jacks plus cable boots take real width, and small cases with a PSU shroud or drive cage below the slot can make cable routing awkward. ## Product Info | Item | Value | | --- | --- | | Chip | Intel I226 | | Port count | 4 | | Supported speeds | 10/100/1000/2500 Mbps | | Bus interface | PCI Express X4 | | PCIe generations | PCIe 3.0 / 2.0 | | Brackets | Full-height / low-profile | | Weight | 0.24 kg | At 0.24 kg this is heavy for a NIC — the mass comes from four controllers plus a passive heatsink. The presence of that heatsink is itself a hint that the card generates real heat. On Amazon. co. **Both figures are point-in-time captures and will not match the current price. To judge value, compare against buying four single-port 2.5GbE cards. What you pay extra for is one slot instead of four, a uniform Intel driver stack, and both brackets in the box. If two ports would do, a dual-port card wins on both price and power. ## Best Use Cases - **DIY router / firewall builders** — pfSense, OPNsense, or OpenWrt setups needing one WAN plus several LAN ports, or physical port separation for VLANs. Intel NICs have a long track record with BSD drivers. - **NAS and hypervisor builders** — Unraid or Proxmox users assigning a dedicated NIC per VM or container, or passing a port straight through to a guest. - **Link aggregation / redundancy** — administrators running LACP for throughput or failover for critical services. - **Slot-constrained machines** — Mini-ITX or slim builds where only one expansion slot is available. - **Industrial and embedded deployments** — 24/7 operation where wired stability outranks everything else. ## Before You Buy **If you only need one port, don't buy this. ** Single-port 2.5GbE cards cost a fraction of the price. The entire value here is density; unused ports are wasted money. "I might expand later" is usually better served by buying again later. **2.5 Gbps requires the other end to cooperate. ** You need a 2.5GbE-capable switch or router and Cat5e-or-better cabling. Plug this into a gigabit switch and you get gigabit — the single most common disappointment with 2.5G upgrades. 2.5GBASE-T is specified to run over Cat5e at short distances, but aging runs or hand-crimped cables can cause unstable links, so use Cat6 or better where you can. **Cooling is passive only. ** Four active controllers produce meaningful heat. In a near-silent case with minimal airflow, or wedged into the bottom of a sealed rack, temperatures can climb and lead to link instability. Aim some airflow across the slot area; pointing one case fan that way is often enough. **The I226 family had reports of link drops and power-saving (EEE/LPI) issues in early revisions. ** You cannot tell from a product page which stepping ships today. If you see link flapping after installation, first disable Energy Efficient Ethernet and link-state power management in the OS, then update to the latest Intel driver. This is standard practice for 2.5GbE NICs generally. **macOS is listed as unsupported** — rule it out for Mac builds. **Amazon listing metadata is occasionally inconsistent with the physical product. ** Seller, fulfiller, and model-number fields are not always kept current. Before ordering, confirm the port count and bracket shape in the product images and check the model number in the title yourself. For production use, it is worth cross-shopping long-established options such as Intel's own four-port server adapters. ## How It Compares Within four-port cards, the right pick depends on the speed you actually need. If gigabit suffices, a mature four-port NIC like Intel's I340-T4 is cheaper and better documented. If you need 10GbE-class aggregate bandwidth, a dual-port SFP+ or SFP28 card delivers more total throughput. This card owns the middle ground: RJ45 copper, several ports, faster than 1 Gbps, but without committing to 10GbE infrastructure — a bigger niche than it sounds. If your real goal is better wireless, a Wi-Fi 6/6E card is the more relevant purchase. ## FAQ **Q. Can I use a PCIe x1 slot? ** A. Not unless the slot is open-ended, since the connector is physically X4. Even then, bandwidth is limited to x1. **Q. Can all four ports run at 2.5 Gbps simultaneously? ** A. Aggregate demand is about 10 Gbps, which PCIe 3.0 x4 can carry in theory. Real throughput still depends on CPU, drivers, and switch configuration. **Q. Does it work with pfSense / OPNsense? ** A. FreeBSD and pfSense are listed as supported, and Intel NICs are well proven on BSD. **Q. Does it work on macOS? ** A. macOS is not in the supported OS list. Treat it as unsupported. **Q. Can I do LACP link aggregation? ** A. That is an OS and switch feature rather than a card feature. Linux bonding, Windows Server NIC teaming, and a LACP-capable switch will do it. **Q. Do I need extra cooling? ** A. The heatsink is passive, so some case airflow is advisable. Avoid running all four ports at full load in a sealed enclosure. ### Product Disclosure (Amazon) - Manufacturer: Buacoz - Seller: KooShop - Fulfilled by: KooShop - ASIN: B0DNJVBHSW - Note: This article covers a manufacturer-made product based on Amazon listing details.