control panel -> power options, pick a plan -> edit plan settings -> change advanced power settings -> processor power management -> maximum processor state
I have an FX 9370, and I ran into similar issues when running it at full. The cpu itself doesn’t overheat because mine is liquid cooled as well, and caps out around 45c, but the VRMs on the motherboard get too hot and cause problems. If you’re certain the cpu itself isn’t inadequately cooled try just ghetto rigging a case fan to blow on the vrms, as that more or less solved my issue.