Thank you for your recommendation. I've looked at some of those SoCs and they're impressive but none of them do what I'm looking for. I want to make a graveyard for my old GPUs, but without the power overhead I have right now with them configured as essentially a mining rig that's folding proteins instead of guessing the hash. I understand that the potential power saved by using ARM or RISC over x86/64 is a few dozen watts at best and chosing an SoC over a desktop platform hamstrings any opportunity for scaling, but it's been a dream project of mine for quite some time. It doesn't have to be practical.
Whenever I am doing different projects I go with RasPi alternatives. I agree they're cheaper and superior.