I have the same problem
My sensor temp commonly gives readings as high as 69c. I havent seen smoke yet.lol
I think the sensor is off.
I have a 1.8a/epox 4sda overclocked to 2.2g. Prime crashes at 2.4, but all other benchmarks run fine at 2.4g
Games won't run stable at 2.4 either. So, I set it back.
cheers