That is disappointing, AOS would run on a 68000 and 512K ram, what more does AROS do to justify the faster cpu and 6M ram?
i think the previous answers to that are not exactly spot on. sorry pals.
its true that aros has been developed on comparatively fast x86, but is meant as cross platform and attempts to be also usable on lower end devices such as pi, or the 68k hardware. it isnt optimized enough yet, but the advance towards those lower end systems, in particular genuine amigas forces it into optimizations that could be avoided before. i can observe it very well, running it regularly on amiga hardware. it has become at least two time faster in the last time. its progressing constantly.
also 68k maintainers like winuae autor, toni willen, attempt to allow it run on lowest end hardware possible. aros is compiled without 020 and higher optimizations for now so far i know, so theoretically should run on 68000 cpu with enough ram. on the other hand the question is, why would anyone need or want to substitute operating system on unexpanded a500. no applications need it or could take advantage of additional features on such a limited system, that is actually best used with its genuine 1.3 kickstart. so why bother?
what concerns the system speed and demands, its wirth to mention that on cpu bound tasks, aros is exactly as fast as the genuine aos (i have benchmarked this). the memory allocation is still some 4 times slower i guess, but it is worked on and also tlsf gets implemented. remember also that systems like 3.9 have their demands as well, dont run within 512k ram and need more time to boot. my a4000/060 cold boots from slow internal ide with old slow 1.3 gig drive almost in a half minute, while almost half of that time the drive is spinning up and aros gets softkicked on genuine kickstart after reboot, aros loading up to full desktop/wanderer/workbench would be about 20 seconds then. but booting it to the shell without startup-sequence will take almost an instant.