Last month, we reported about a major flaw within the Intel I225-V 'Foxville' networking chip which Intel claimed to have been fixed with a newer revision which was shipping in Z490 motherboards that are now available on retail shelves, however, test results from our sources show that the issue still persists and several Z490 motherboards featuring the Foxville controller could remain affected and unable to deliver the advertised networking speeds that a 2.5GbE networking controller should deliver.
Intel Foxville I225-V 2.5GbE Networking Issues Still Persist, Several Z490 Motherboards Seemingly Affected With Proper Hardware Fix Coming In Second Half of 2020
Intel's I225-V network controller which is codenamed Foxville aims to deliver 2.5GbE networking speeds. It is part of the new 400-series chipset based motherboards and one of the highlighted features of the platform. The I225-V 'Foxville' is a 2.5Gbe network controller which is designed to standardize 2.5Gbe LAN across the mainstream platform. Intel's network controllers are used on both Intel's own chipset based motherboards and also those that feature AMD's chipsets.
Last month, a report emerged that the controller had a built-in flaw that led to packet loss and reduced network performance in the range of 1-10 Mb/s. A list of mitigations with the current silicon of the I225-V controller was mentioned by Intel which simply advises users/OEMs to set the Foxville Controller link to operate at 1 Gb/s which was far less than what Intel had advertised.
Intel officially responded to us on the matter, claiming that the latest production version of the Foxville silicon known as 'V2' was already in production which has been integrated on several Z490 motherboards now shipping in retail channels. This new B2 stepping has indeed been featured on several Z490 motherboards however, as I mentioned above, our sources seem to indicate that the issue isn't fully resolved.
Following wasIntel's official response on the matter:
"Intel is committed to delivering the highest levels of product quality and has already corrected the issue in the latest production version of the silicon. I225 v2 is already in production. We identified an IEEE spec variance in the Intel Ethernet Controller I225 that results in performance degradation when paired with some 2.5GbE switches and routers. Consumers experiencing this issue should ensure they have the latest software driver and associated firmware installed and can refer to https://www.intel.com/i225v1 for compatible switches and routers to ensure 2.5Gb/s connectivity."
In the networking performance tests conducted by our source, the B2 stepping on a retail Z490 motherboard delivering speeds of around 255 MB/s (2.05 Gbps) transfer speeds (without switch) and even worse speeds of 144 - 194 MB/s (<2.0 Gbps) when using a Netgear XS505M switch.
In comparison, a Z490 motherboard with a 3rd party 2.5 GbE networking switch delivers consistent speeds with our without the use of a switch. From what we have managed to gather, it looks like a large list of Z490 motherboards, primarily from ASUS and Gigabyte, could be affected by this issue since they're still relying on the B2 stepping of the chip. Other Z490 vendors rely on 3rd party net-working controllers so this issue is nonexistent for them.
So the question remains, when can users expect a proper fix to the networking issue? Again, this requires a hardware-level fix, and the B2 stepping boards will remain affected although Intel can try to mitigate the issue in the future with new firmware releases. Intel is planning to commence production of the Foxville B3 stepping chip by June of 2020 with hardware-level solidifications in place which should root out the issue once and for all. Also, we will have to wait for more testing with various other switches to see how widespread this issue is.