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Green PCB with silver heatsink and two RJ45 ports on a PCIe bracket

SMUGDESK

SMUGDESK Dual Port 2.5G PCIe x1 Ethernet NIC Realtek RTL8125BG 2×RJ45 2500Mbps

SKU CH-ZKS4-RG49Z

Adds two 2.5G Ethernet ports to a desktop PC via a PCIe 2.1 x1 slot for 2500Mbps bandwidth over existing Cat5e cabling

  • Dual 2.5G ports deliver 2500Mbps over existing Cat5e cabling
  • Realtek RTL8125BG controller auto-negotiates 2.5G/1G/100M/10Mbps under IEEE802.3bz
  • PCIe 2.1 x1 fits x1/x4/x8/x16 slots for simple desktop install
  • Hardware checksum offload and 9KB Jumbo Frames cut CPU load
  • Passive heatsink and per-port LEDs ensure stable 24/7 operation

Dual-port 2.5G network card

The SMUGDESK adapter adds two independent 2.5GbE RJ45 ports to a desktop PC through a single PCIe 2.1 x1 slot. It is built around the Realtek RTL8125BG controller and works with existing Cat5e or Cat6 cabling up to 100 metres. The card suits NAS link aggregation, soft-router builds and replacement of failed onboard LAN.

Passive heatsink and power saving

A passive heatsink keeps the controller stable during 24/7 continuous operation without adding fan noise. Hardware TCP/UDP checksum offload lowers CPU occupancy while IEEE802.3az EEE reduces power draw during light traffic. Separate LINK/ACT LEDs on each port give instant visual confirmation of link status and data activity.

PCIe 2.1 x1 slot requirement

Installation needs a free PCIe x1, x4, x8 or x16 slot running at Gen 2.1 or later; the card will not fit systems that lack this slot type. Official drivers cover Windows 10, Windows 11, Windows Server and mainstream Linux distributions including Ubuntu, CentOS and Debian.

Highlights

  • Dual 2.5G ports deliver 2500Mbps over existing Cat5e cabling
  • Realtek RTL8125BG controller auto-negotiates 2.5G/1G/100M/10Mbps under IEEE802.3bz
  • PCIe 2.1 x1 fits x1/x4/x8/x16 slots for simple desktop install
  • Hardware checksum offload and 9KB Jumbo Frames cut CPU load
  • Passive heatsink and per-port LEDs ensure stable 24/7 operation

Specifications

No published specifications for this item yet.

Questions about this item

How do I install the PCIe 2.1 x1 card in a desktop motherboard?

Insert the card into any free PCIe x1, x4, x8 or x16 slot; the 2.1 x1 interface is backward compatible so it fits wider slots without an adapter. Secure the bracket screw and attach the driver from the Realtek RTL8125BG package for Windows 10, 11, Server or mainstream Linux.

What maintenance will the dual-port adapter need over time?

The passive heatsink requires only occasional dust removal with compressed air to keep 24/7 operation stable; driver updates from Realtek for the RTL8125BG controller should be applied when the OS prompts.

At what throughput does the PCIe 2.1 x1 bus limit sustained transfers?

The single-lane PCIe 2.1 link caps aggregate bandwidth at roughly 500 MB/s, so combined traffic on both 2.5G RJ45 ports will hit that ceiling before the 2500Mbps line rate does.

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