The transition to 2.5Gbps Ethernet has not been an easy one for Intel. The company's I225/I226 2.5 GbE Ethernet controllers (codename Foxville), a prevalent choice on Intel platform motherboards for the last few years, has presented a fair share of issues since its introduction, including random networking disconnections and stuttering. And while Intel has been working through the issues with multiple revisions of the hardware, they apparently haven't hammered out all of the bugs yet, as evidenced by the latest bug mitigation suggestion from the company. In short, Intel is suggesting that users experiencing connection issues on the latest I226-V controller disable some of the its energy efficiency features, which appear to be a major contributor in the connection stability issues I226-V has been seeing.

To mitigate the connection problems on the I226-V Ethernet controller, Intel is advising affected users to disable Energy-Efficient Ethernet (EEE) mode through Windows Device Manager. The same guidance applies to Linux users as well. EEE mode aims to lower power consumption when the Ethernet connection is in an idle state. The issue is that EEE mode seems to activate when an Ethernet connection is in active use, causing it to drop out momentarily.

And while deactivating EEE does reportedly improve connection stability, deactivating it doesn't seem to be the ultimate solution. Intel has received reports that some users still experienced disconnections with EEE mode disabled. Furthermore, disabling EEE mode forgoes its intended benefits – such as reducing power draw by up to 50% when an Ethernet connection is idling – so it's not an option that cost-conscious consumers would normally want to disable.

Intel has also released an updated driver set for the I226-V/I225-V family of Ethernet controllers that automatically makes this adjustment. Specifically, the patch deactivates EEE mode for connection speeds above 100 Mbps, but users may have to disable it entirely if the workaround doesn't work with their combination of hardware. MSI and Asus have already deployed the new Ethernet driver for their respective Intel 700-series motherboards, so other vendors shouldn't take long to do the same.

In the interim, Intel will continue investigating the root cause and provide a concrete solution for motherboards with the I226-V Ethernet controller. The Foxville family of Intel Ethernet controllers has a long history of connectivity quirks – going back to the original I225-V in 2019 and E3100 in 2020 – ultimately requiring multiple hardware revisions (B1, B2, & B3 steppings) before finding solutions to many of its issues. As a result, it's not off the table that the I226-V Ethernet controller may suffer the same fate.