Raise use afterburner 800 - 820 (default voltage 0.988v) and Temperature will safelly at 60C ( some people had bad air flow ran at 64C) at fulload benchmark / test stabillity. It will fine and safe.
~MAX Overclock with original voltage MSI 570 TFIII~
Clocks: 840/2000, Core Voltage: 0.988v , Avg. FPS: 58.5, Max temp: 61C, Max Fan Speed (Auto): 56%
I saw some people oc it at 870/1750/2000 with voltage 1.075v and fan speed at 75%.
Also In revew it can potensial increase 20% I think that need raise voltage and raise fan at 99% .. Wow noise. And risky to get artifact.