ASRock has developed a card that can expand a certain B650 motherboard via a specific connection as if it were an X670 motherboard. It seems to be mainly an I/O expansion in the form of extra USB and M.2 connections and faster network support.
LevelOneTechs has a video dedicated to the so-called X670 Xpansion Kit. This website has tested this expansion card in combination with a B650 LiveMixer motherboard from ASRock. The card adds a second chipset to this motherboard. X670 motherboards have two Promontory 21 chipsets, while B650 motherboards have to make do with a single one. Additional options are available in the motherboard bios to manage the second chipset.
The expansion card contains two M.2 slots with PCIe 4.0 x4, three USB-A connections, a USB-C connection up to 10Gbit/s, two SATA connections and a 10GbE connection. The latter is perhaps the most eye-catching addition, because the tested motherboard does not exceed 2.5GbE in terms of network speed support.
Bron: LevelOneTechs
The X670 Xpansion Kit must be connected in a specific way, namely via PCIe in combination with a special cable, a control line which requires a J2 header on the motherboard. As a result, the card will only work on certain motherboards.
It is unclear if this X670 Xpansion Kit expansion card is a product that will be released in this form and if so, when this product will be released. It seems to be a copy that has been further developed than just a prototype. The B650 LiveMixer motherboard used by LevelOneTechs has also not been officially released yet.
