What to look for in a Single-board Computer for running Urbit
Thinking about buying a Raspberry Pi just to run Urbit on it? I suggest you don’t - you can do better than a Raspberry Pi! They’re the most popular brand, and have the widest number of compatible accessories, but CPU and storage are both slower on the Raspberry Pi than on alternatives with the same or slightly higher price.
The Pi4 is powered by a BCM2711 with four Cortex-A72 cores running @ 1.5GHz. When looking for more performant chips search for something with at least two cores of Cortex-A72 design or better (eg Cortex-A73, Cortex-A75, etc) and with a higher frequency than 1.5GHz. Currently, the more powerful mainstream Pi alternatives are powered by the Rockchip RK3399, Amlogic S922X, or Amlogic A311D.
The Pi4 has very limited options for storage: either microSD cards that might be more prone to corruption and are restricted to the speed of the Pi’s reader even if the card is of high quality, or through USB adapters that might have buggy chipsets or may not support UASP. So be on the lookout for Pi alternatives with an eMMC module, an m.2 NVMe socket, or the ability to add on PCIe devices through a hat or riser.
A good place to start looking for RPi alternatives is HackerBoards.
At this point in time I’m a fan of the RK3399 powered NanoPi M4V2 which has a nice passive heatsink option, or a metal case with fan and NVMe adapter. (Note that you won’t be able to boot from an NVMe drive on the NanoPi M4V2, you’ll still need at least a boot partition on an eMMC module or SD card.) For an option that looks less like a traditional Pi but has a more powerful CPU, consider an ODroid N2+.