why I dont use CPU temps for regulating anything. If you do you will spend all day listening to the fans go up and down when a fly lands on your case.
Sorry to disagree with you a lot lately Justin but that's not true. Might be for you, who knows how you have your system set up, but it shouldn't be.
My CPU temp at idle is 24-25 degrees only one degree variation at idle. Pretty consistent under load too. Nothing that would cause fans to ramp up and down all the time.
All of the fans in my case  are PWM fans regulated by the CPU temperature and controlled by Fan Xpert 3. They don't ramp up and down all the time at all. Even less chance of such a thing given that Fan Xpert has the facility to modify how quickly the fans ramp up.
My CPU fan is running at a very quiet and very constant 333 RPM at idle. One or two rpm variation, that's all.
As I type this my case fans are at a very quiet and constant 600 RPM. There is some variation but only minor and inaudible. Same under load, very consistent, no ramping up and down at all.
As you can see, the CPU temps tend to spike with every minor PC activity, opening a folder, moving mouse cursor around the screen...etc.
The old AI Suite 2 did not display such variations!
Then if you look at T_Sensor1, it shows a temp of 33C even though there is no sensor plugged into the header on the Mobo.
On the other hand, the PCH temps show random dips into 0C.
So, is it the software that's malfunctioning, the sensors that are defective or is it my CPU cooling system?
As far as CPU cooling, I'm using a 212 EVO with push-pull configuration. Ambient air inside the case is around 24 C with a total of 7 fans running.
Are you using the latest BIOS and latest version of AiSuite? Don't forget there are always plenty of BIOS updates with a new platform.
Is it usual to see 0C and minus temps off/on? Should I worry about it or is it usual that sensors just go crazy sometimes?
One point to remember though is that you should never run two temp measuring utilities simultaneously or they can mess each other up. Always one at a time.