This conflict typically arises from programs reading the socket temp (a sensor on the motherboard under the CPU socket) instead of the core temp as reported by the CPU.
Unfortunately, AMD hasn't released thermal info for anything other than Phenom 2/Thuban. What we do know came from this AMD post and many seem to use it as guidelines for AMD's current generation of CPUs. This info may or may not apply to FX, Llano, and Trinity (it probably doesn't). For example, AMD recommended staying 28C below the thermal shutoff for Thuban; this same delta puts max FX temps at 55C for daily usage. Given the different process nodes and voltages between Thuban and FX, I have a hard time believing such inferences are accurate.
http://www.overclock.net/t/1128821/amd-temp-information-and-guide
Sorry I didn't get back to you sooner, I just recently had your email forwarded to my department.
Concerning your question regarding the temperatures with your processor. (1090) the maximum temperature threshold is 62 Celsius which set for the internal die (core) temperature of the chip. The core temperatures have an equational offset to determine temperature which equalizes at about 45 Celsius thus giving you more accurate readings at peak temperatures. The hindrance in this is the sub ambient idle temperature readings you speak of.
The silicon and adhesives used in manufacturing these processors has a peak temperature rating of 97+ Celsius before any form of degradation will take place. The processor also has a thermal shut off safe guard in place that shuts the processor down at 90 Celsius.
The Cpu temperature is read form a sensor embedded within the socket of your motherboard causing about a 7-10 Celsius variance form the actual Cpu temperature, which may be what you are reading about on the net.
You can use an application called AMD overdrive, that will allow you to monitor your temperatures accurately.
As long as your core temperature has not exceeded the high side of the 60 degree mark for extended periods of time you should be ok. 62 degrees holds a generous safety net to begin with.
I hope I was able to answer your questions, If you have any more inquiries don't hesitate to contact us.
Thank You
Alex Cromwell
Senior Technology Director
Advanced Micro Devices
If we assume AMD used some of the same implementations in FX, then:
1) Idle temps are still inaccurate
2) There is still no per-core temperature sensor
3) AMD recommends a large safety net between the thermal shutoff point and the recommended everyday usage temperature.
4) There also still doesn't appear to be any thermal throttling in FX; instead, it merely shuts down (observed by IDC's post)
AMD has recommended using either AMD Overdrive or CoreTemp. Presumably any other monitoring program with results that match either of these could also be accepted as working.