ppc is still a thing, my project computer is a power9. The only reason it isn't my daily driver is because I can't help but tinker with it. Being able to rewrite the supervisor chip code in order to get that fan curve just so, and having the support of unabridged and NDA free documentation - instead of grinding through reverse engineering... feels good. I highly recommend it, just stick to known working GPUs, the mmu actually does its job.