AMD specs say it's good up to 85C. Most people don't like to see it over 60 though. Keep in mind, if you aren't sure if you're reading the thermal diode temp and not the socket temp, then you're not reading the thermal diode, and the thermal diode tells you how hot the core actually is, and it's usually at least 5 C over the temp reading the socket gives. For example, my diode reading says 49C right now while running SETI@Home, and the socket temp says 43.