There aren't a lot of Mini ITX motherboards for AMD's Ryzen but that will change as ASUS is getting ready to launch two new boards for Ryzen.
In a response to an inquiry from German tech site ComputerBase, ASUS revealed its ROG STRIX X370-I Gaming and ROG STRIX B350-I Gaming will start shipping next month.
These boards are based on the AMD X370 and B350 chipsets, respectively. An official announcement from ASUS with photos and specifications is expected in about two weeks but the actual availability of the boards isn't planned until mid or late October.
At the moment, there are just five Mini-ITX motherboards for the Socket AM4 platform. ASRock has a X370 and B350 board, Biostar offers the same and Gigabyte has a sole B350 offering.