Ideally I'd love to have at least 512MB of ram. I realize that's overkill for a lot of applications, but it'd give me confidence it can run a reasonably competent Linux userland.
Try it right here:
https://bellard.org/jslinux/vm.html?cpu=riscv64&url=fedora33...
It's slow the first time as it loads things over the network, but once files are cached in the browser it takes 5 seconds to boot to a shell prompt and 2.5 seconds to gcc compile helloworld.
You can run GNU "screen" to make a couple of panes and run "top" in one and see there is a good amount of free RAM even when running emacs.
This JS emulation runs at around the speed of maybe a 200 MHz CPU. The 1 GHz C906 in the Milk-V Duo is probably about five times faster, and the 480 MHz C910 in the BL808 chip on the M1s and Ox64 is several times faster as well.
Quite usable speed, comparable to the original Raspberry Pi. Just not enough RAM to run a modern GUI is all.
On a 128MB wifi router this all & a lot of other small utils fits okay ish, runs fine, while routing. 256MB vastly preferred.
Hell, in the late 90s I was running that kind of stuff on Linux on a Pentium with 32 MB total RAM, not >32 MB free after booting.
Wifi routers tend to be much bigger class devices but 128mb is very common, 256 pretty establishdd. It's just nice not feeling super space constrainted. This isn't rocket science, we shouldn't have to obsess over payload size. The cost should be so small. Albeit yet at scale some folks do have cause to pinch those pennies, it's not a good general computing path.