The problem is that the architecture in question would take forever in cpu time terms to switch back and forth, so a sprinkle of heavy avx512 was the worst of a

The problem is that the architecture in question would take forever in cpu time terms to switch back and forth, so a sprinkle of heavy avx512 was the worst of all worlds. In addition, some cpus would emulate 512 with half width micro-ops during voltage ramp up. Yes, it sounds crazy.