[ OpenBSD related discussion removed] It may be this problem is not software related. Try to check the following: - thermal paste from the CPU is not dry (remove it anyway and reapply a fresh one) - heatsink fins are not filled in with dust (if so, clean it) - heatpipes, if present on heatsink, are sealed and not broken. Advanced boards provide CPU fan throttle for you by default, but if you have some issue the fan will automatically spin on to compensate if it can.
Good luck.
