I'm gonna give my own experiences with FX chips.
My idle temps, reported by CoreTemp, Aida64, HWMonitor, OCCT, and some others, fluctuate quite a bit among them.. Form example, CoreTemp says my idle temps are around 11°C, which is impossible due to the room temps: 28-30°C.. Good bye Thermodynamics..
If I run a stress test like OCCT, which has its own charts, I can peak as much as 75°C with no safe shutdown. Obviously, I had to stop the test, but not a single crash or hard reset due to the CPU safe temps. The max operational safe temp is 60-65°C..
Besides, asking in other forums, some people says that the FXs chips tends to missread temps.. I don't know what to believe, but of course I shouldn't peak at 75°C in a test without having a CPU safe-temp shutdown.. So maybe there's some truth on that..
Here, something to read (sorry if I post another forum's thread. If not allowed, please edit):
In short, I don't have a "real" value of my CPU temps, just a mid term if I look all of them. Maybe you have to do something like that once you change your PSU.. Like most have said here, that voltage readings are not good..
8320 @ 4,7 / 990FXA UD5 / CF-X 7970 + 7950 / Switch 810 / H110 p-p / 16 GB RAM / 23" 5760x1080 / SSD 64GB RAID0 / HX750 / SB Recon3D Fatal1ty Champion / z506