Gigabyte as well, like all others really, is working on Mini-ITX Ryzen motherboards. The first one would be the AB350N-Gaming WiFi, and sure chances are high that is a B350 based :)
The board specs have leaked based on a presentation that Gigabyte gave in japan. The AB350N-Gaming WiFi will get two DIMM slots, Gigabyte Ethernet and obviously 802.11acWIFI. Audio is managed by a Realtek ALC 1220 codec and the one PCIe slot will be metal shielded, that would be a single x16 slot. We're confident that the board Will receive the right amount of RGB LEDs as well considering RGB FUSION LED light show design is mentioned as well.
Gigabyte Working on Mini-ITX Ryzen motherboard
