SiFive has announced a mini-ITX motherboard [cnx-software.com] with its SiFive Freedom U740:
At the heart of the SiFive board is a SiFive FU740 processor coupled with 8 GB DDR4 memory and 32 MB SPI Flash. It comes with a 4x USB 3.2 ports and a 16x PCIe expansion slot. The mini-ITX standard form factor makes it easy to build a RISC-V PC.
[...] SiFive Unmatched board will be available by Q4'20 for USD 665, and you can already register your interest. You will get a mini-ITX board, 32 GB MicroSD, and 3-meter CAT5e ethernet cable. SiFive did not speak on the commercial aspect of the product but are very confident about future development. Android and Chrome support is something we can see in the future. The product looks promising and we are excited to see future development in the RISC-V PC ecosystem.
Performance will probably be comparable to a Raspberry Pi 3. Alternatively:
Powered by Microchip PolarFire RISC-V SoC FPGA, PolarBerry is both a single board computer with Gigabit Ethernet and 40-pin GPIO header, as well as a system-on-module thanks to three Samtec board-to-board connectors.
[...] PolarBerry is not available just yet, but LinuxGizmos reports [linuxgizmos.com] the SBC/SoM will be soon launched on Crowd Supply [crowdsupply.com] for $995 and shipments are expected to start in January 2021. Besides the aforementioned crowdfunding page, additional details may be found on the product page [sundancedsp.com].
Previously: SiFive to Debut a RISC-V PC for Developers in October [soylentnews.org]