Depends on how much the CPU can lower power consumption. With Intel parts you can run them with no cooler, they'll just throttle to maintain 100 °C by default

Depends on how much the CPU can lower power consumption. With Intel parts you can run them with no cooler, they'll just throttle to maintain 100 °C by default (exactly like in laptops). Not every motherboard allows this though, some will start beeping angrily when PROCHOT is asserted or reset. With Ryzens it depends, the chiplet ones can't do it, because the IOD power consumption exceeds what the IHS can dissipate without a cooler, so no matter what the CPU power management does, it will always eventually shut off. If you're in OC mode, it will do so at 115 °C. The APUs can probably do it, they'll probably be faster than Intel because they're more efficient. CPUs without an IHS just explode though.