https://en.m.wikipedia.org/wiki/Brain_in_a_vat
A problem can't be solved on its own plane, so no amount of raw processing power can escape such a sandbox IMHO, but there can be flaws inadvertently introduced into the system via fuzzing:
https://en.m.wikipedia.org/wiki/Fuzz_testing
Many have already reported that mundane reality is a tiny sliver of what's actually going on, under the influence of psychedelics, for example.