The problem is that Intel is really sluggish without the Turbo Boost feature. You see this with Intel Mac laptops if you disable TB or you have low battery power and the system disables it. It becomes real sluggish. When Intel needs a little horse power to do anything then it heats up dramatically and this is its Achilles heel in that the ARM based Macs don't heat up at all during that initial burst of speed which probably doesn't last very long. But even on sustained throughput the heat generated by the ARM chip is very low due to using such little power.