AMD 64 X2:
Maximum CPU Temperature | Hardware Secrets
Depending on the specific CPU, your limit will be from as low as 63 up to 72.
I've got three of these, all 89W units, usually in the 30-40 degree range, all with stock AMD cooler & fan. One PC CPU does tend to get noticeably hotter than the others in the summer - I'm not sure if this is an airflow or thermal paste problem - and the fans are definitely busier as a result. Still only gets up to 51-52, ambient around 28.
SD