Usally if the system freezes or reboots with out error its Vcore.
First is your system stable at stock speeds? If not you needed to start there. Are you using the latest bios version? If not flash to the latest version and load optimized defaults/save and exit/ renter bios and make changes to get your ram running at its rated speed. save and reboot.
Post your full bios settings that are currently failing for your current speed.