Yeah theoretically but is there a reason you have the voltage so high? Were you unable to achieve a substantial overclock with lower voltage? The voltage may be causing the artifacting. I personally wouldn't be comfortable with those temps. As for the safe zones, all cards are created differently so maybe you got one that can't handle as high of overclocks? I'm not sure. I would definitely back it down to see if the problems still persist. The few fps you would gain from a 900 and 927 overclock would be minimal and not worth the heat and artifact problems.