Hardkernl NetCard 3 is an expansion card with four 5Gbps Ethernet ports designed for the ODROID-H3 and ODROID-H4 SBCs and adding to the two 2.5GbE ports on the Intel Jasper Lake and Alder Lake-N single board computers.
It follows the H2 Net Card with four 2.5GbE ports introduced in 2021 for the ODROID-H2, and tested by Ian with the ODROID-H3+ SBC in 2023. Hardkernel ended up selling more than expected, so they designed the Netcard 3 with 5GbE ports as an upgrade. It remains to be seen whether 5Gbps networking will be as popular as 2.5GbE or users will prefer moving to 10GbE hardware instead…
NetCard 3 specifications:
- 4x 5Gbps Ethernet ports via RealTek RTL8126 5GbE controllers.
- M.2 edge connector with PCIe Gen3 x4 signaling
- Cooling with a long heatsink on RTL8126 controllers
- Compatible with ODROID-H3/H3+ and ODROID-H4/H4+ only, and not earlier ODROID-H2/H2+ boards
You may need to flash a different BIOS version as needs to be done for the M.2 2×2 and M.2 4×1 cards for the ODROID-H3/H4. That’s because by default the board is configured as non-bifurcated PCIe Gen 3 x4, but the Netcard 3 expects four bifurcated PCIe Gen 3 x1 lanes. As explained in the wiki, you can check the BIOS by going to Chipset->PCH-IO Configuration->PCI Express Configuration->PCI Express Root Port 5/6/7/8 and check whether they use bifurcated x1 lanes.
If that’s not the case, you’ll need to download the BIOS for your board currently “ADLN-H4_B1.08-4X1_netcard.bin” for the ODROID-H4 boards and “JSL-H3_B1.17_4x1_netcard.bin” for the ODROID-H3 series. BIOS update is done using a USB flash drive. All instructions are provided in the aforementioned wiki.
![ODROID-H4 Type 2 Case with 2.5GbE 5GbE ports ODROID-H4 Type 2 Case with 2.5GbE 5GbE ports](https://www.cnx-software.com/wp-content/uploads/2025/02/ODROID-H4-Type-2-Case-2.5GbE-5GbE-ports-720x482.webp)
The NetCard 3 works with ODROID-H4 Type 2, 3, and 4 cases, as well as ODROID-H3 Type 5, 6, 7 enclosures. The RTL8126 controller should be supported in Linux 6.9 and up, but Hardkernel still points to the Windows and Linux drivers on RealTek website.
Hardkernel tested the 5GbE ports using an ODROID-H4+, an ODROID-H4 Ultra, and a 10GbE switch using iperf3. The interfaces were all saturated (4.5 to 4.67 Gbps each) with a combined ~18 Gbps throughput and the CPU usage was about 20% while running iperf3 on all four interfaces.
Hardkernel sells the Net Card 3 for $68.00 plus shipping. For reference, the Net Card 2 with 2.5GbE ports (Intel I226-V) goes for $47 and RTL8126 M.2 and PCIe cards with a single port now sell for around $12 to $25.
Thanks to Domih for the tip.
![Jean Luc Aufranc](https://www.cnx-software.com/wp-content/uploads/2023/05/Jean-Luc-Aufranc.webp)
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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[ nice value for this price (thx) ]