If you're looking to build small and want to walk the path of AMD Ryzen, MSI has an answer for you in the form of its new B350I Pro AC Mini-ITX motherboard. This itty bitty offering has pretty much all you need and very little you don't.
The board has two DIMM slots that can be filled with 32 GB of DDR4 memory running at up to 3200 MT/s in a dual-channel setup. The single PCIe x16 slot is metal-reinforced, and there are four SATA ports and an M.2 socket.
The B350I Pro AC is well-equipped in the external connections department. There's onboard 802.11ac Wi-Fi, Bluetooth 4.2, and Gigabit Ethernet for networking purposes. If you're going to plug peripherals into the board, there are two each of USB 3.0 and USB 3.1 Gen2 Type-A ports. Onboard video connections include one DisplayPort 1.2 output and an HDMI 1.4 port.
The board has a nine-phase PWM design, something that MSI says is a first on an AM4 Mini-ITX motherboard. There are also two headers for RGB LED strips that can be controlled through MSI's Mystic Light software.
MSI hasn't made release or pricing information available, but looking at the other B350 Mini-ITX boards available over at Newegg, we'd expect to see it somewhere around the $120 to price range when it does hit shelves.