Fan speeds keep jumping

[Aivar]

My fan speeds keep jumping both in bios and speedfan. They go from 0 RPM straigt to 300000/600000 RPM back to 20000PM and so on and so on. It seems like that the actual fan speed is not affected by this and fan speed changes depending on usage.

I had this problem on my old motherboard and thought that the mobo was the issue, but after my old mobo died(started to give blue screens and random freezes) and I got the new one, this problem is still there.
My old motherboard was ASUS M5A97 LE R2.0 and my current one is Gigabyte 970A-DS3P FX. My cooler is arctic freezer pro 13, but the same issue happens also with the case fan.
What can possibly be the solution. It doesn't affect the performance at all, but it's a bit annoying to have your fan speeds jump and fool around like that in my opinion.

 

[Paperdoc]

The speeds you report are impossible, of course. You say this happens with both fans, eh? From your post I presume there are only those two fans in your system. Am I correct to assume that the Artic Freezer Pro is plugged into the CPU_FAN header, and the case ventilation fan into a mobo SYS_FAN or CHA_FAN header?

The only thing I can suggest is that you check the connections for the fans to their mobo headers. If there is a loose connection that makes and loses contact often, that might give the header a noisy signal that could be read badly.

 

[Aivar]

There is no loose connection unless there is one inside the plug. It also happened on old motherboard, but on this one at least it sometimes shows kinda realistic speed.

 

[Paperdoc]

A loose connection inside the plug is certainly possible, but I would NOT expect that to affect BOTH of your fans. You say both exhibit the same problem. Is that confirmed?

 

[Aivar]

A loose connection inside the plug is certainly possible, but I would NOT expect that to affect BOTH of your fans. You say both exhibit the same problem. Is that confirmed?

Yes. Both off them do it. Also, in speedfan my temp2 and 3 get up to 85-90 C under load(games and video editing). CPU also gets to 80 degree. All temp monitors I have show the same(even gigabyte app).
My processor is 4GHZ but it shows 4.2 in Gigabyte app and maxes at 4.5 sometimes in Gigabyte monitor.